C++ Tutorial/vector/vector insert — различия между версиями

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Версия 14:21, 25 мая 2010

Combine insert and end to add elements to the end of vector

#include <iostream>
#include <cassert>
#include <algorithm>
#include <string>
#include <list>
#include <deque>
#include <vector>
using namespace std;
int main()
{
  vector<string> vec;

  vec.insert(vec.end(), "AAA");
  vec.insert(vec.end(), "BBBB");
  vec.insert(vec.end(), "CCCCC");

  vector<string>::iterator pos;

  for (pos=vec.begin(); pos!=vec.end(); ++pos) {
        cout << *pos << " ";
  }
  return 0;
}
AAA BBBB CCCCC

Insert 10 duplicate value to vector

#include <iostream>
#include <vector>
using namespace std;
int main()
{
  vector<char> v(10);
  vector<char> v2;
  char str[] = "<Vector>";
  unsigned int i;
  for(i=0; i<10; i++) 
     v[i] = i + "a";
  for(i=0; str[i]; i++) 
     v2.push_back(str[i]);
  
  cout << "Original contents of v:\n";
  for(i=0; i<v.size(); i++) 
      cout << v[i] << " ";
  cout << "\n\n";
  vector<char>::iterator p = v.begin();
  p += 2; // point to 3rd element
  v.insert(p, 10, "X");
  // display contents after insertion
  cout << "Size after inserting X"s = " << v.size() << endl;
  cout << "Contents after insert:\n";
  for(i=0; i<v.size(); i++) cout << v[i] << " ";
  cout << "\n\n";
  return 0;
}
Original contents of v:
a b c d e f g h i j
Size after inserting X"s = 20
Contents after insert:
a b X X X X X X X X X X c d e f g h i j

Insert 25 at the beginning

#include <vector>
#include <iostream>
using namespace std;
int main ()
{
    // Instantiate a vector with 4 elements, each initialized to 90
    vector <int> v (4, 90);
    // Insert 25 at the beginning
    v.insert (v.begin (), 25);
    
    vector <int>::iterator i;
    for ( i = v.begin (); i != v.end (); ++ i )
    {
        cout << *i << " ";
    }
    return 0;
}

Insert 2 numbers of value 45 at the end

#include <vector>
#include <iostream>
using namespace std;
int main ()
{
    // Instantiate a vector with 4 elements, each initialized to 90
    vector <int> v (4, 90);
    vector <int>::iterator i;
    for ( i = v.begin (); i != v.end (); ++ i ){
        cout << *i << " ";
    }
    // Insert 2 numbers of value 45 at the end
    v.insert (v.end (), 2, 45);
    cout << "The vector after inserting two elements at the end: ";
    for ( i = v.begin (); i != v.end (); ++ i )
    {
        cout << *i << " ";
    }
    return 0;
}

Insert element by index

#include <iostream>
using std::cout;
using std::endl;
#include <vector>    // vector class-template definition
#include <algorithm> // copy algorithm
#include <iterator>  // ostream_iterator iterator
#include <stdexcept> // out_of_range exception
int main()
{
   int array[ 6 ] = { 1, 2, 3, 4, 5, 6 };
   std::vector< int > integers( array, array + 6 );
   std::ostream_iterator< int > output( cout, " " );
   integers.push_back( 2 );
   integers.push_back( 3 );
   integers.push_back( 4 );
   cout << "Vector integers contains: ";
   std::copy( integers.begin(), integers.end(), output );
   // insert 22 as 2nd element
   integers.insert( integers.begin() + 1, 22 );
   cout << "\n\nVector integers contains: ";
   std::copy( integers.begin(), integers.end(), output );
   return 0;
}
Vector integers contains: 1 2 3 4 5 6 2 3 4
Vector integers contains: 1 22 2 3 4 5 6 2 3 4

Insert elements from array

#include <iostream>
using std::cout;
using std::endl;
#include <vector>    // vector class-template definition
#include <algorithm> // copy algorithm
#include <iterator>  // ostream_iterator iterator
#include <stdexcept> // out_of_range exception
int main()
{
   int array[ 6 ] = { 1, 2, 3, 4, 5, 6 };
   std::vector< int > integers( array, array + 6 );
   std::ostream_iterator< int > output( cout, " " );
   integers.push_back( 2 );
   integers.push_back( 3 );
   integers.push_back( 4 );
   cout << "Vector integers contains: ";
   std::copy( integers.begin(), integers.end(), output );
   // insert elements from array
   integers.insert( integers.begin(), array, array + 6 );
   cout << "\n\nContents of vector integers before clear: ";
   std::copy( integers.begin(), integers.end(), output );

   return 0;
}
Vector integers contains: 1 2 3 4 5 6 2 3 4
Contents of vector integers before clear: 1 2 3 4 5 6 1 2 3 4 5 6 2 3 4

Insert one vector to another vector

#include <iostream>
#include <vector>
using namespace std;
int main()
{
  vector<char> v(10);
  vector<char> v2;
  char str[] = "<Vector>";
  unsigned int i;
  for(i=0; i<10; i++)
     v[i] = i + "a";
  for(i=0; str[i]; i++)
     v2.push_back(str[i]);
  cout << "Original contents of v:\n";
  for(i=0; i<v.size(); i++)
      cout << v[i] << " ";
  cout << "\n\n";
  vector<char>::iterator p = v.begin();
  p += 2; // point to 3rd element
  v.insert(p, 10, "X");
  // display contents after insertion
  cout << "Size after inserting X"s = " << v.size() << endl;
  cout << "Contents after insert:\n";
  for(i=0; i<v.size(); i++) cout << v[i] << " ";
  cout << "\n\n";

  // Insert v2 into v
  v.insert(p, v2.begin(), v2.end());
  cout << "Size after v2"s insertion = ";
  cout << v.size() << endl;
  cout << "Contents after insert:\n";
  for(i=0; i<v.size(); i++) cout << v[i] << " ";
  cout << endl;
  return 0;
}
Original contents of v:
a b c d e f g h i j
Size after inserting X"s = 20
Contents after insert:
a b X X X X X X X X X X c d e f g h i j

Insert the contents of the array into the end of the vector

#include <vector>
#include <iostream>
using namespace std;
int main(int argc, char** argv)
{
  int arr[10]; // normal C++ array
  vector<int> vec; // STL vector
  int i;
  // Initialize each element of the array to the value of its index.
  for (i = 0; i < 10; i++) {
    arr[i] = i;
  }
  // Insert the contents of the array into the end of the vector.
  vec.insert(vec.end(), arr, arr + 10);
  // print the contents of the vector
  for (i = 0; i < 10; i++) {
    cout << vec[i] << " ";
  }
  return (0);
}

Insert two elements from another container in position [1]

#include <vector>
#include <iostream>
using namespace std;
int main ()
{
    // Instantiate a vector with 4 elements, each initialized to 90
    vector <int> v (4, 90);
    vector <int>::iterator i;
    for ( i = v.begin (); i != v.end (); ++ i ){
        cout << *i << " ";
    }
    vector <int> vecAnother (2, 30);
    v.insert (v.begin () + 1,vecAnother.begin (), vecAnother.end ());
    for ( i = v.begin (); i != v.end (); ++ i )
    {
        cout << *i << " ";
    }
    return 0;
}
Источник — «http://cppe.ru/index.php?title=C%2B%2B_Tutorial/vector/vector_insert&oldid=2231»