C++/Data Structure/Vector Utility — различия между версиями

Текущая версия на 10:24, 25 мая 2010

Содержание

1 Another way to sort a sequence into descending order.
2 A vector may allocate more memory than it currently needs.
3 Demonstrate back_insert_iterator in vector
4 Demonstrate binary_search() in vector
5 Demonstrate count_if and not1 in vector
6 Demonstrate find() and find_if() in vector
7 Demonstrate front_insert_iterator in vector
8 Demonstrate insert_iterator in a vector
9 Demonstrate lower_bound() in vector
10 Demonstrate mismatch() in vector
11 Demonstrate random_shuffle() in vector
12 Demonstrate search() in vector
13 Demonstrating partial_sort() in vector
14 Demonstrating remove() and replace() in vector
15 Demonstrating sort() in vector
16 Demonstrating unique() in vector
17 Exchange elements from two different types of containers.
18 Find minimum and maximum inside a vector
19 Generating a sequence in vector
20 Insert one vector into another using an insert iterator
21 Merge two sequences
22 Right-rotate a sequence in vector
23 Rotate a sequence in vector
24 set_union, set_difference, set_symmetric_difference, set_intersection
25 Sorting a vector into descending order in vector
26 Transforming a sequence in vector
27 Use a function adaptor in vector
28 Use a unary function object to determine even/odd.
29 Use for_each() in vector
30 Use the logical_not unary function object in vector
31 Using copy() in Vector
32 Using swap_ranges() in Vector

Another way to sort a sequence into descending order.

#include <iostream>
#include <vector>
#include <algorithm>
#include <functional>
using namespace std;
int main()
{
  vector<char> vectorObject(26);
  int i;
  for(i = 0; i <vectorObject.size(); i++) 
     vectorObject[ i ] = "A"+i;
  cout << "Original ordering of vectorObject:";
  for(i = 0; i <vectorObject.size(); i++)
    cout << vectorObject[ i ] << " ";
  cout << endl;
  
  sort(vectorObject.begin(), vectorObject.end(), not2(less<char>()));   // sort into desceding order
  cout << "After sorting vectorObject using not2(less<char>()):";
  for(i = 0; i <vectorObject.size(); i++)
    cout << vectorObject[ i ] << " ";
  return 0;
}

A vector may allocate more memory than it currently needs.

#include <iostream>
#include <vector>
using namespace std;
int main()
{
  vector<char> vectorObject(10);
  cout << "Initial size: " << vectorObject.size() << endl;
  cout << "Initial capacity: " << vectorObject.capacity();
  cout << "\n\n";
 
  vectorObject.push_back("X");
  cout << "Size after push_back: " << vectorObject.size() << endl;
  cout << "New capacity: " << vectorObject.capacity();
  cout << "\n\n";
  vectorObject.resize(100);
  cout << "Size after resize: " << vectorObject.size() << endl;
  cout << "Capacity after resize: " << vectorObject.capacity();
  cout << "\n\n";
  vectorObject.push_back("Y");
  cout << "Size after push_back: " << vectorObject.size() << endl;
  cout << "New capacity: " << vectorObject.capacity();
  cout << "\n\n";
  return 0;
}

Demonstrate back_insert_iterator in vector

#include <iostream>
#include <iterator>
#include <vector>
using namespace std;
int main()
{
  vector<int> vectorObject, vectorObject2;
  vector<int>::iterator itr;
  int i;
  for(i = 0; i <5; i++)
    vectorObject.push_back(i);
  cout << "Original contents of vectorObject: ";
  itr = vectorObject.begin();
  while(itr != vectorObject.end())
    cout << *itr++ << " ";
  cout << endl;

  back_insert_iterator<vector<int> > bck_i_itr(vectorObject);   // create a back_insert_iterator to vectorObject
  *bck_i_itr++ = 100;        // insert rather than overwrite at end
  *bck_i_itr = 200;
  cout << "vectorObject after insertion: ";
  itr = vectorObject.begin();
  while(itr != vectorObject.end())
    cout << *itr++ << " ";
  cout << endl;
  cout << "Size of vectorObject2 before copy: " << vectorObject2.size() << endl;
  copy(vectorObject.begin(), vectorObject.end(), back_inserter(vectorObject2));   // copy vectorObject to vectorObject2 using back inserter
  cout << "Size of vectorObject2 after copy: " << vectorObject2.size() << endl;
  cout << "Contents of vectorObject2 after insertion: ";
  itr = vectorObject2.begin();
  while(itr != vectorObject2.end())
    cout << *itr++ << " ";
  return 0;
}

Demonstrate binary_search() in vector

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main()
{
  vector<char> vectorObject;
  bool result;
  int i;
  for(i = 0; i <10; i++)
    vectorObject.push_back("A" + i);
  cout << "Contents of vectorObject: ";
  for(i = 0; i <vectorObject.size(); i++)
    cout << vectorObject[ i ];
  cout << endl;
  
  cout << "Looking for F.";
  result = binary_search(vectorObject.begin(), vectorObject.end(), "F");
  if(result)
    cout << "F Found";
  else
    cout << "F Not Found";
  cout << "Looking for X.\n";
  result = binary_search(vectorObject.begin(), vectorObject.end(), "X");
  if(result)
    cout << "X Found\n";
  else
    cout << "X Not Found\n";
  return 0;
}

Demonstrate count_if and not1 in vector

#include <iostream>
#include <vector>
#include <functional>
#include <algorithm>
using namespace std;
int main()
{
  vector<char> vectorObject;
  int num;
  int i;
  for(i = 0; i <26; i++) 
     vectorObject.push_back(i+"A");
  cout << "Sequence contains:";
  for(i = 0; i <vectorObject.size(); i++)
    cout << vectorObject[ i ] << " ";
  cout << endl;
  num = count_if(vectorObject.begin(), vectorObject.end(), bind2nd(greater<int>(), "r"));
  cout << "There are " << num;
  cout << " elements greater than E.\n";
  num = count_if(vectorObject.begin(), vectorObject.end(), not1(bind2nd(greater<int>(), "r")));
  cout << "There are " << num;
  cout << " elements not greater than E.";
  return 0;
}

Demonstrate find() and find_if() in vector

#include <iostream>
#include <vector>
#include <algorithm>
#include <cstring>
using namespace std;
bool iscomma(char ch) {
  if(ch == ",") 
     return true;
  return false;
}
int main()
{
  vector<char> vectorObject;
  vector<char>::iterator p;
  char str[] = "One, Two, Three, Four, Five, Six";
  int i;
  for(i = 0; i < strlen(str); i++)
    vectorObject.push_back(str[ i ]);
  cout << "Contents of vectorObject: ";
  for(i = 0; i < vectorObject.size(); i++)
    cout << vectorObject[ i ];
  cout << endl;
  
  p = find(vectorObject.begin(), vectorObject.end(), "T");          // find the first T
  cout << "Sequence beginning with T: ";
  while(p != vectorObject.end())
    cout << *p++;
  cout << endl;
  p = find_if(vectorObject.begin(), vectorObject.end(), iscomma);   // find first comma
  cout << "After find first comma: ";
  while(p != vectorObject.end())
    cout << *p++;
  cout << endl;
  return 0;
}

Demonstrate front_insert_iterator in vector

#include <iostream>
#include <iterator>
#include <list>
using namespace std;
int main()
{
  list<int> vectorObject, vectorObject2;
  list<int>::iterator itr;
  int i;
  for(i = 0; i <5; i++)
    vectorObject.push_back(i);
  cout << "Original contents of vectorObject: ";
  itr = vectorObject.begin();
  while(itr != vectorObject.end())
    cout << *itr++ << " ";
  cout << endl;
  front_insert_iterator<list<int> > frnt_i_itr(vectorObject);  // create a front_insert_iterator to vectorObject

  *frnt_i_itr++ = 100;   // insert rather than overwrite at front
  *frnt_i_itr = 200;
  cout << "vectorObject after insertion: ";
  itr = vectorObject.begin();
  while(itr != vectorObject.end())
    cout << *itr++ << " ";
  cout << endl;
  cout << "Size of vectorObject2 before copy: " << vectorObject2.size() << endl;
  copy(vectorObject.begin(), vectorObject.end(), front_inserter(vectorObject2));
  cout << "Size of vectorObject2 after copy: " << vectorObject2.size() << endl;
  cout << "Contents of vectorObject2 after insertion: ";
  itr = vectorObject2.begin();
  while(itr != vectorObject2.end())
    cout << *itr++ << " ";
  return 0;
}

Demonstrate insert_iterator in a vector

#include <iostream>
#include <iterator>
#include <vector>
using namespace std;
int main()
{
  vector<int> vectorObject;
  vector<int>::iterator itr;
  int i;
  for(i = 0; i <5; i++)
    vectorObject.push_back( i );
  cout << "Original contents of vectorObject: ";
  itr = vectorObject.begin();
  while(itr != vectorObject.end())
    cout << *itr++ << " ";
  cout << endl;
  itr = vectorObject.begin();
  itr += 2; // point to element 2

  insert_iterator<vector<int> > i_itr(vectorObject, itr);  // create insert_iterator to element 2
 
  *i_itr++ = 100;    // insert rather than overwrite
  *i_itr = 200;
  cout << "vectorObject after insertion: ";
  itr = vectorObject.begin();
  while(itr != vectorObject.end())
    cout << *itr++ << " ";
  return 0;
}

Demonstrate lower_bound() in vector

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main()
{
  vector<char> vectorObject;
  vector<char>::iterator p;
  int i;
  for(i = 0; i <10; i++)
    vectorObject.push_back("A" + i);
  cout << "Contents of vectorObject: ";
  for(i = 0; i <vectorObject.size(); i++)
    cout << vectorObject[ i ];
  cout << endl;
  cout << "Looking for F...";
  p = lower_bound(vectorObject.begin(), vectorObject.end(), "F");
  if(p != vectorObject.end())
    cout << *p << " Found";
  else
    cout << "F Not Found";
  cout << "\n Looking for X.";
  p = lower_bound(vectorObject.begin(), vectorObject.end(), "X");
  if(p != vectorObject.end())
    cout << *p << " Found";
  else
    cout << "X Not Found";
  return 0;
}

Demonstrate mismatch() in vector

#include <iostream>
#include <vector>
#include <algorithm>
#include <cstring>
#include <utility>
using namespace std;
int main()
{
  vector<char> vectorObject, vectorObject2;
  pair<vector<char>::iterator, vector<char>::iterator> p;
  char str1[] = "O, T, T, T";
  char str2[] = "O, T, F, F, N";
  int i;
  for(i = 0; i <strlen(str1); i++)
    vectorObject.push_back(str1[ i ]);
  for(i = 0; i <strlen(str2); i++)
    vectorObject2.push_back(str2[ i ]);
  cout << "Contents of vectorObject:  ";
  for(i = 0; i <vectorObject.size(); i++)
    cout << vectorObject[ i ];
  cout << endl;
  cout << "Contents of vectorObject2: ";
  for(i = 0; i <vectorObject2.size(); i++)
    cout << vectorObject2[ i ];
  cout << endl;

  p = mismatch(vectorObject.begin(), vectorObject.end(), vectorObject2.begin());   // find the first mismatch
  if(p.first != vectorObject.end()) {                        // mismatch found
    cout << "The character " << *p.first;
    cout << " in vectorObject mismatches the character ";
    cout << *p.second << " in vectorObject2.";
  }
  return 0;
}

Demonstrate random_shuffle() in vector

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main()
{
  vector<char> vectorObject;
  int i;
  for(i = 0; i <26; i++) 
     vectorObject.push_back("A"+i);
  cout << "Original contents of vectorObject:\n";
  for(i = 0; i <vectorObject.size(); i++)
    cout << vectorObject[ i ];
  cout << endl;
  random_shuffle(vectorObject.begin(), vectorObject.end());
  cout << "Shuffled contents of vectorObject:\n";
  for(i = 0; i <vectorObject.size(); i++)
    cout << vectorObject[ i ];
  return 0;
}

Demonstrate search() in vector

#include <iostream>
#include <vector>
#include <algorithm>
#include <cstring>
using namespace std;
int main()
{
  vector<char> vectorObject, vectorObject2;
  vector<char>::iterator p;
  char str1[] = "O, T, T, T";
  char str2[] = "T";
  int i;
  for(i = 0; i <strlen(str1); i++)
    vectorObject.push_back(str1[ i ]);
  for(i = 0; i <strlen(str2); i++)
    vectorObject2.push_back(str2[ i ]);
  cout << "Contents of vectorObject: ";
  for(i = 0; i <vectorObject.size(); i++)
    cout << vectorObject[ i ];
  cout << endl;
  p = search(vectorObject.begin(), vectorObject.end(), vectorObject2.begin(), vectorObject2.end()); // find the first Two
  cout << "Sequence beginning with T: ";
  
  while(p != vectorObject.end())
    cout << *p++;
  cout << endl;
  return 0;
}

Demonstrating partial_sort() in vector

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
void init_vectorObject(vector<int> &vectorObject)
{
  vectorObject[0] = 1;
  vectorObject[1] = 10;
  vectorObject[2] = 2;
  vectorObject[3] = -3;
  vectorObject[4] = 9;
  vectorObject[5] = 4;
  vectorObject[6] = 8;
  vectorObject[7] = 5;
  vectorObject[8] = 7;
  vectorObject[9] = 6;
}
int main()
{
  vector<int> vectorObject(10);
  int i;
  init_vectorObject(vectorObject);
  cout << "Original order:";
  for(i = 0; i <10; i++) 
    cout << vectorObject[ i ] << " ";
  cout << endl;
  partial_sort(vectorObject.begin(), vectorObject.begin()+5, vectorObject.end());
  cout << "Order after partial sorting:";
  for(i = 0; i <10; i++) 
    cout << vectorObject[ i ] << " ";
  cout << endl;
  return 0;
}

Demonstrating remove() and replace() in vector

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main()
{
  vector<char> vectorObject;
  vector<char>::iterator p, p_end;
  int i;
  for(i = 0; i <5; i++) {
    vectorObject.push_back("A"+i);
    vectorObject.push_back("A"+i);
    vectorObject.push_back("A"+i);
  }
  cout << "Original contents of vectorObject:";
  for(p = vectorObject.begin(); p < vectorObject.end(); p++)
    cout << *p << " ";
  cout << endl;
  
  p_end = remove(vectorObject.begin(), vectorObject.end(), "C");    // remove all C"s
  cout << "Sequence after removing all C"s:";
  for(p = vectorObject.begin(); p < p_end; p++)
    cout << *p << " ";
  cout << endl;

  replace(vectorObject.begin(), vectorObject.end(), "D", "X");     // replace D"s with digits X"s
  cout << "Sequence after replacement:";
  for(p = vectorObject.begin(); p < p_end; p++)
    cout << *p << " ";
  cout << endl;
  return 0;
}

Demonstrating sort() in vector

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
void init_v(vector<int> &vectorObject)
{
  vectorObject[0] = 1;
  vectorObject[1] = 10;
  vectorObject[2] = 2;
  vectorObject[3] = -3;
  vectorObject[4] = 9;
  vectorObject[5] = 4;
  vectorObject[6] = 8;
  vectorObject[7] = 5;
  vectorObject[8] = 7;
  vectorObject[9] = 6;
}
int main()
{
  vector<int> vectorObject(10);
  int i;
  // sort the entire container
  init_v(vectorObject);
  cout << "Sort an entire container.";
  cout << "Original order:";
  for(i = 0; i <10; i++) 
    cout << vectorObject[ i ] << " ";
  cout << endl;
  sort(vectorObject.begin(), vectorObject.end());
  cout << "Order after sorting container:";
  for(i = 0; i <10; i++) 
    cout << vectorObject[ i ] << " ";
  cout << endl;
  // sort a subset of the container
  init_v(vectorObject); 
  
  cout << "Sort a subset of a container.";
  cout << "Original order:";
  for(i = 0; i <10; i++) 
    cout << vectorObject[ i ] << " ";
  cout << endl;
  sort(vectorObject.begin() + 2, vectorObject.end() - 2);
  cout << "Order after sorting vectorObject[2] through vectorObject[7]:";
  for(i = 0; i <10; i++) 
    cout << vectorObject[ i ] << " ";
  cout << endl;
  return 0;
}

Demonstrating unique() in vector

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main()
{
  vector<char> vectorObject;
  vector<char>::iterator p, p_end;
  int i;
  for(i = 0; i <5; i++) {
    vectorObject.push_back("A"+i);
    vectorObject.push_back("A"+i);
    vectorObject.push_back("A"+i);
  }
  cout << "Original contents of vectorObject:\n";
  for(p = vectorObject.begin(); p < vectorObject.end(); p++)
    cout << *p << " ";
  cout << endl;
  
  p_end = unique(vectorObject.begin(), vectorObject.end());       // remove duplicates
  cout << "Sequence after removing duplicates:\n";
  for(p = vectorObject.begin(); p < p_end; p++)
    cout << *p << " ";
  cout << endl;
  return 0;
}

Exchange elements from two different types of containers.

#include <iostream>
#include <vector>
#include <deque>
#include <algorithm>
using namespace std;
int main()
{
  vector<char> vectorObject(10);
  deque<char> deq(10);
  int i;
  for(i = 0; i < 10; i++) 
     vectorObject[ i ] = "A" + i;
  for(i = 0; i < 10; i++) 
     deq[ i ] = "0" + i;
  cout << "Original contents of vectorObject:";
  for(i = 0; i < 10; i++)
    cout << vectorObject[ i ] << " ";
  cout << endl;
  
  cout << "Original contents of deq:";
  for(i = 0; i < 10; i++)
    cout << deq[ i ] << " ";
  cout << endl;
  // swap ranges in vectorObject and deq
  swap_ranges(vectorObject.begin() + 2, vectorObject.end() - 3, deq.begin() + 4);
  cout << "Contents of vectorObject after swap:";
  for(i = 0; i < 10; i++)
    cout << vectorObject[ i ] << " ";
  cout << endl;
  
  cout << "Contents of deq after swap:";
  for(i = 0; i < 10; i++)
    cout << deq[ i ] << " ";
  cout << endl;
  return 0;
}

Find minimum and maximum inside a vector

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main()
{
  vector<int> vectorObject(5);
  int i;
  vectorObject[0] = 1;
  vectorObject[1] = 2;
  vectorObject[2] = 5;
  vectorObject[3] = 9;
  vectorObject[4] = 2;
  cout << "Contents of vectorObject: ";
  for(i = 0; i <vectorObject.size(); i++)
    cout << vectorObject[ i ] << " ";
  cout << endl;
  cout << "Maximum element is: ";
  cout << *max_element(vectorObject.begin(), vectorObject.end());
  cout << endl;
  cout << "Minimum element is: ";
  cout << *min_element(vectorObject.begin(), vectorObject.end());
  return 0;
}

Generating a sequence in vector

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

double f()                  // A simple generator function.
{
  static double val = 1.0;
  double t;
  t = 1.0 / val;
  val += val;
  return t;
}
int main()
{
  vector<double> vectorObject(5);
  int i;

  generate(vectorObject.begin(), vectorObject.end(), f);     // generate a series
  cout << "Series: ";
  for(i = 0; i <vectorObject.size(); i++)
    cout << vectorObject[ i ] << " ";
  return 0;
}

Insert one vector into another using an insert iterator

#include <iostream>
#include <iterator>
#include <vector>
#include <string>
using namespace std;
int main()
{
  vector<string> vectorObject, vectorObject2;
  vector<string>::iterator itr;
  vectorObject.push_back("T");
  vectorObject.push_back("S");
  vectorObject.push_back("A");
  vectorObject.push_back("P");
  vectorObject2.push_back("A");
  vectorObject2.push_back("I");
  vectorObject2.push_back("S");
  cout << "Original size of vectorObject: " << vectorObject.size() << endl;
  cout << "Original contents of vectorObject:\n";
  itr = vectorObject.begin();
  while(itr != vectorObject.end())
    cout << *itr++ << " ";
  cout << endl;
  copy(vectorObject2.begin(), vectorObject2.end(), inserter(vectorObject, vectorObject.begin() + 2));
  cout << "Size of vectorObject after insertion: ";
  cout << vectorObject.size() << endl;
  cout << "Contents of vectorObject after insertion:";
  itr = vectorObject.begin();
  while(itr != vectorObject.end())
    cout << *itr++ << " ";
  return 0;
}

Merge two sequences

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main()
{
  vector<char> vectorObject1, vectorObject2, vectorObject3(26);
  int i;
  for(i = 0; i <26; i+=2) 
      vectorObject1.push_back("A"+i);
  for(i = 0; i <26; i+=2) 
      vectorObject2.push_back("B"+i);
  cout << "Original contents of vectorObject1:";
  for(i = 0; i <vectorObject1.size(); i++)
    cout << vectorObject1[ i ];
  cout << endl;
  cout << "Original contents of vectorObject2:";
  for(i = 0; i <vectorObject2.size(); i++)
    cout << vectorObject2[ i ];
  cout << endl;
  
  merge(vectorObject1.begin(), vectorObject1.end(),    // merge sequences
        vectorObject2.begin(), vectorObject2.end(),
        vectorObject3.begin());
  cout << "Result of merge:\n";
  for(i = 0; i <vectorObject3.size(); i++)
    cout << vectorObject3[ i ];
  return 0;
}

Right-rotate a sequence in vector

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main()
{
  vector<int> vectorObject;
  vector<int>::iterator p;
  int i;
  
  for(i = 0; i <10; i++) 
     vectorObject.push_back(i);
  cout << "Original ordering: ";
  for(p=vectorObject.begin(); p<vectorObject.end(); p++)
    cout << *p << " ";
  cout << endl;
  // rotate right two positions using reverse iterators
  rotate(vectorObject.rbegin(), vectorObject.rbegin()+2, vectorObject.rend());
  cout << "Order after two right rotates: ";
  for(p=vectorObject.begin(); p<vectorObject.end(); p++)
    cout << *p << " ";
  cout << endl;
  return 0;
}

Rotate a sequence in vector

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main()
{
  vector<int> vectorObject;
  vector<int>::iterator p;
  int i;
  
  for(i = 0; i <10; i++) 
     vectorObject.push_back(i);
  cout << "Original ordering: ";
  for(p=vectorObject.begin(); p<vectorObject.end(); p++)
    cout << *p << " ";
  cout << endl;
  rotate(vectorObject.begin(), vectorObject.begin()+1, vectorObject.end());   // rotate left one position
  cout << "Order after left rotate: ";
  for(p=vectorObject.begin(); p<vectorObject.end(); p++)
    cout << *p << " ";
  cout << endl;
  return 0;
}

set_union, set_difference, set_symmetric_difference, set_intersection

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main()
{
  vector<char> vectorObject1, vectorObject2, v_res(26), vectorObject3;
  vector<char>::iterator p, pres_end;
  int i;
  for(i = 0; i <20; i++) 
      vectorObject1.push_back("A"+i);
  for(i=10; i <26; i++) 
      vectorObject2.push_back("A"+i);
  cout << "Contents of vectorObject1:\n";
  for(i = 0; i <vectorObject1.size(); i++)
    cout << vectorObject1[ i ];
  cout << endl;
  cout << "Contents of vectorObject2:\n";
  for(i = 0; i <vectorObject2.size(); i++)
    cout << vectorObject2[ i ];
  cout << endl;
  pres_end = set_union(vectorObject1.begin(), vectorObject1.end(), vectorObject2.begin(), vectorObject2.end(), v_res.begin());
  cout << "Set union: ";
  for(p=v_res.begin(); p!=pres_end; p++)
    cout << *p;
  cout << endl;
  pres_end = set_difference(vectorObject1.begin(), vectorObject1.end(), vectorObject2.begin(), vectorObject2.end(), v_res.begin());
  cout << "Set difference: ";
  for(p=v_res.begin(); p!=pres_end; p++)
    cout << *p;
  cout << endl;
  pres_end = set_symmetric_difference(vectorObject1.begin(), vectorObject1.end(), vectorObject2.begin(), vectorObject2.end(), v_res.begin());
  cout << "Set symmetric difference: ";
  for(p=v_res.begin(); p!=pres_end; p++)
    cout << *p;
  cout << endl;
  pres_end = set_intersection(vectorObject1.begin(), vectorObject1.end(), vectorObject2.begin(), vectorObject2.end(), v_res.begin());
  cout << "Set intersection: ";
  for(p=v_res.begin(); p!=pres_end; p++)
    cout << *p;
  cout << endl;
  // includes 
  vectorObject3.push_back("A");
  vectorObject3.push_back("C");
  vectorObject3.push_back("D");
  if(includes(vectorObject1.begin(), vectorObject1.end(), vectorObject3.begin(), vectorObject3.end()))
      cout << "vectorObject1 includes all of vectorObject3.";
  else
      cout << "vectorObject3 contains elements not found in vectorObject1.";
  return 0;
}

Sorting a vector into descending order in vector

#include <iostream>
#include <vector>
#include <algorithm>
#include <functional>
using namespace std;
int main()
{
  vector<char> vectorObject(26);
  int i;
  for(i = 0; i <vectorObject.size(); i++) 
     vectorObject[ i ] = "A"+i;
  cout << "Original ordering of vectorObject:";
  for(i = 0; i <vectorObject.size(); i++)
    cout << vectorObject[ i ] << " ";
  cout << endl;
  // sort into desceding order
  sort(vectorObject.begin(), vectorObject.end(), greater<char>());
  cout << "After sorting vectorObject using greater():";
  for(i = 0; i <vectorObject.size(); i++)
    cout << vectorObject[ i ] << " ";
    
  return 0;
}

Transforming a sequence in vector

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
double midpoint(double a, double b)
{
  return ((a-b) / 2) + b;
}
int main()
{
  vector<double> vectorObject1(5), vectorObject2(5), vectorObject3(5);
  int i;
  vectorObject1[0] = 110.0;
  vectorObject1[1] = 918.6;
  vectorObject1[2] = 112.23;
  vectorObject1[3] = 818.8;
  vectorObject1[4] = -212.01;
  vectorObject2[0] = 21.0;
  vectorObject2[1] = 31.3;
  vectorObject2[2] = 41.19;
  vectorObject2[3] = 155.0;
  vectorObject2[4] = -2.0;
  cout << "Values in vectorObject1: ";
  for(i = 0; i <vectorObject1.size(); i++)
    cout << vectorObject1[ i ] << " ";
  cout << endl;
  cout << "Values in vectorObject2: ";
  for(i = 0; i <vectorObject2.size(); i++)
    cout << vectorObject2[ i ] << " ";
  cout << endl;
  
  transform(vectorObject1.begin(), // find midpoints between elements in vectorObject1 those in vectorObject2
            vectorObject1.end(), 
            vectorObject2.begin(),
            vectorObject3.begin(), 
            midpoint);
  cout << "Midpoints: ";
  for(i = 0; i <vectorObject3.size(); i++)
    cout << vectorObject3[ i ] << " ";
  return 0;
}

Use a function adaptor in vector

#include <iostream>
#include <vector>
#include <algorithm>
#include <functional>
#include <cstring>
using namespace std;
int main()
{
  vector<char *> vectorObject;
  vector<char *>::iterator p;
  int i;
  vectorObject.push_back("One");
  vectorObject.push_back("Two");
  vectorObject.push_back("Three");
  vectorObject.push_back("Four");
  vectorObject.push_back("Five");
  cout << "Sequence contains:";
  for(i = 0; i <vectorObject.size(); i++)
    cout << vectorObject[ i ] << " ";
  cout << endl;
  cout << "Searching sequence for Three.\n";
  // use a pointer-to-function adaptor
  p = find_if(vectorObject.begin(), vectorObject.end(), not1(bind2nd(ptr_fun(strcmp), "Three")));
  if(p != vectorObject.end()) {
    cout << "Found.";
    cout << "Sequence from that point is:";
    do {
      cout << *p++ << " ";
    } while (p != vectorObject.end());
  }
  return 0;
}

Use a unary function object to determine even/odd.

#include <iostream>
#include <vector>
#include <algorithm>
#include <functional>
using namespace std;
class isEven: public unary_function<int, bool> {
public:
  result_type operator()(argument_type i)
  { 
    return (result_type) !(i%2);
  }
};
int main()
{
  vector<int> vectorObject;
  int i;
  for(i = 1; i < 20; i++) 
     vectorObject.push_back(i);
  cout << "Sequence:";
  for(i = 0; i <vectorObject.size(); i++)
    cout << vectorObject[ i ] << " ";
  cout << endl;
  i = count_if(vectorObject.begin(), vectorObject.end(), isEven());
  cout << i << " numbers are evenly divisible by 2.";
  return 0;
}

Use for_each() in vector

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
void show(int i)
{
  cout << i << " ";
}
int main()
{
  vector<int> vectorObject;
  int i;
  for(i = 0; i <10; i++) 
     vectorObject.push_back(i);
  cout << "Contents of vectorObject: ";
  for_each(vectorObject.begin(), vectorObject.end(), show);
  cout << endl;
  return 0;
}

Use the logical_not unary function object in vector

#include <iostream>
#include <vector>
#include <functional>
#include <algorithm>
using namespace std;
int main()
{
  vector<bool> vectorObject;
  int i;
  for(i = 1; i < 10; i++) 
     vectorObject.push_back((bool)(i % 2));
  cout << boolalpha;                // turn on boolalpha I/O flag
  cout << "Original contents of vectorObject:";
  for(i = 0; i <vectorObject.size(); i++)
    cout << vectorObject[ i ] << " ";
  cout << endl;
 
  // use the logical_not function object
  transform(vectorObject.begin(), vectorObject.end(), vectorObject.begin(), logical_not<bool>()); 
  cout << "Inverted contents of vectorObject:";
  for(i = 0; i <vectorObject.size(); i++)
    cout << vectorObject[ i ] << " ";
  cout << endl;
  return 0;
}

Using copy() in Vector

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main()
{
  vector<char> vectorObject(10);
  vector<char> vectorObject2(10);
  int i;
  for(i = 0; i < 10; i++) 
     vectorObject[ i ] = "A" + i;
  for(i = 0; i < 10; i++) 
     vectorObject2[ i ] = "z";
  
  copy(vectorObject.begin(), vectorObject.end(), vectorObject2.begin());   // copy all of vectorObject into vectorObject2
  cout << "Contents of vectorObject2 after copy:\n";
  for(i = 0; i < 10; i++)
    cout << vectorObject2[ i ] << " ";
  cout << endl;
  
  for(i = 0; i <10; i++)                  // re-initialize vectorObject2
     vectorObject2[ i ] = "z";
  
  copy(vectorObject.begin() + 2, vectorObject.end() - 2, vectorObject2.begin()); // now copy just part of vectorObject into vectorObject2
  cout << "Contents of vectorObject2 after subsequence copy:\n";
  for(i = 0; i <10; i++)
    cout << vectorObject2[ i ] << " ";
  cout << endl;

  for(i = 0; i <10; i++)                  // re-initialize vectorObject2
     vectorObject2[ i ] = "z";
  // now copy part of vectorObject into middle of vectorObject2
  copy(vectorObject.begin() + 2, vectorObject.end() - 2, vectorObject2.begin() + 3);
  cout << "Contents of vectorObject2 after copy into middle:\n";
  for(i = 0; i <10; i++)
    cout << vectorObject2[ i ] << " ";
  cout << endl;
  return 0;
}

Using swap_ranges() in Vector

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main()
{
  vector<char> vectorObject(10);
  vector<char> vectorObject2(10);
  int i;
  for(i = 0; i < 10; i++) 
     vectorObject[ i ] = "A" + i;
  for(i = 0; i < 10; i++) 
     vectorObject2[ i ]  = "0" + i;
  cout << "Original contents of vectorObject:";
  for(i = 0; i < 10; i++)
    cout << vectorObject[ i ] << " ";
  cout << endl;
  
  cout << "Original contents of vectorObject2:";
  for(i = 0; i < 10; i++)
    cout << vectorObject2[ i ] << " ";
  cout << endl;
  // swap ranges in vectorObject and vectorObject2
  swap_ranges(vectorObject.begin() + 2, vectorObject.end() - 3, vectorObject2.begin() + 4);
  cout << "Contents of vectorObject after swap:";
  for(i = 0; i < 10; i++)
    cout << vectorObject[ i ] << " ";
  cout << endl;
  
  cout << "Contents of vectorObject2 after swap:";
  for(i = 0; i < 10; i++)
    cout << vectorObject2[ i ] << " ";
  cout << endl;
  return 0;
}

Текущая версия на 10:24, 25 мая 2010 (просмотреть исходный код) Admin (обсуждение \| вклад) м (1 версия: Импорт контента...)	Текущая версия на 10:24, 25 мая 2010 (просмотреть исходный код) Admin (обсуждение \| вклад) м (1 версия: Импорт контента...)
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C++/Data Structure/Vector Utility — различия между версиями

Текущая версия на 10:24, 25 мая 2010

Содержание

Another way to sort a sequence into descending order.

A vector may allocate more memory than it currently needs.

Demonstrate back_insert_iterator in vector

Demonstrate binary_search() in vector

Demonstrate count_if and not1 in vector

Demonstrate find() and find_if() in vector

Demonstrate front_insert_iterator in vector

Demonstrate insert_iterator in a vector

Demonstrate lower_bound() in vector

Demonstrate mismatch() in vector

Demonstrate random_shuffle() in vector

Demonstrate search() in vector

Demonstrating partial_sort() in vector

Demonstrating remove() and replace() in vector

Demonstrating sort() in vector

Demonstrating unique() in vector

Exchange elements from two different types of containers.

Find minimum and maximum inside a vector

Generating a sequence in vector

Insert one vector into another using an insert iterator

Merge two sequences

Right-rotate a sequence in vector

Rotate a sequence in vector

set_union, set_difference, set_symmetric_difference, set_intersection

Sorting a vector into descending order in vector

Transforming a sequence in vector

Use a function adaptor in vector

Use a unary function object to determine even/odd.

Use for_each() in vector

Use the logical_not unary function object in vector

Using copy() in Vector

Using swap_ranges() in Vector

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