C++/STL Algorithms Sorting/sort
Содержание
- 1 Sort all element in an array
- 2 Sort a string array with sort()
- 3 Sort a subset of the container
- 4 Sort a vector and print out the sorted elements
- 5 Sort a vector into ascending order of id members
- 6 Sort elements in deque
- 7 Sort elements reversely with custom function
- 8 Sorting user-defined class
- 9 Sort into descending order by using greater
- 10 Sort part of the elements in an array
- 11 Sort random number
- 12 Sort the entire container
- 13 Use custom function and sort to sort strings by length
- 14 Using an in-place generic sort algorithm
- 15 Using the generic sort algorithm with a binary predicate: greater
Sort all element in an array
<source lang="cpp">
/* The following code example is taken from the book
* "The C++ Standard Library - A Tutorial and Reference" * by Nicolai M. Josuttis, Addison-Wesley, 1999 * * (C) Copyright Nicolai M. Josuttis 1999. * Permission to copy, use, modify, sell and distribute this software * is granted provided this copyright notice appears in all copies. * This software is provided "as is" without express or implied * warranty, and with no claim as to its suitability for any purpose. */
- include <iostream>
- include <algorithm>
- include <functional>
- include <iterator>
using namespace std; int main() {
int coll[] = { 5, 6, 2, 4, 1, 3 }; // sort beginning with the second element sort (coll, coll+6); // print all elements copy (coll, coll+6, ostream_iterator<int>(cout," ")); cout << endl;
} /* 1 2 3 4 5 6
*/ </source>
Sort a string array with sort()
<source lang="cpp">
- include <iostream>
- include <algorithm>
- include <string>
using namespace std; int main() {
string words[5] = { "ABCD", "BCDEF", "CERF","DERT", "EFRE"}; string* where; where = find(words, words + 5, "CD"); cout << *++where << endl; sort(words, words + 5); where = find(words, words + 5, "ER"); cout << *++where << endl;
}
</source>
Sort a subset of the container
<source lang="cpp">
- include <cstdlib>
- include <iostream>
- include <vector>
- include <functional>
- include <algorithm>
using namespace std; void show(const char *msg, vector<int> vect); int main() {
vector<int> v(10); for(unsigned i=0; i < v.size(); i++) v[i] = rand() % 100; show("Original order:", v); sort(v.begin()+2, v.end()-2); show("sorting elements v[2] to v[7] into natural order:", v); return 0;
} void show(const char *msg, vector<int> vect) {
cout << msg << endl; for(unsigned i=0; i < vect.size(); ++i) cout << vect[i] << endl;
}
</source>
Sort a vector and print out the sorted elements
<source lang="cpp">
/* The following code example is taken from the book
* "The C++ Standard Library - A Tutorial and Reference" * by Nicolai M. Josuttis, Addison-Wesley, 1999 * * (C) Copyright Nicolai M. Josuttis 1999. * Permission to copy, use, modify, sell and distribute this software * is granted provided this copyright notice appears in all copies. * This software is provided "as is" without express or implied * warranty, and with no claim as to its suitability for any purpose. */
- include <iostream>
- include <vector>
- include <algorithm>
using namespace std; int main() {
vector<int> coll; vector<int>::iterator pos; // insert elements from 1 to 6 in arbitrary order coll.push_back(2); coll.push_back(5); coll.push_back(4); coll.push_back(1); coll.push_back(6); coll.push_back(3); // sort all elements sort (coll.begin(), coll.end()); // print all elements for (pos=coll.begin(); pos!=coll.end(); ++pos) { cout << *pos << " "; }
}
/*
1 2 3 4 5 6
*/ </source>
Sort a vector into ascending order of id members
<source lang="cpp">
- include <iostream>
- include <cassert>
- include <vector>
- include <algorithm>
- include <functional>
using namespace std; class MyClass : public binary_function<MyClass, MyClass, bool> { public:
int id; bool operator()(const MyClass& x, const MyClass& y) const { return x.id >= y.id; } friend ostream& operator<<(ostream& o, const MyClass& x) { o << x.id; return o; }
}; int main() {
vector<MyClass> vector1(100); for (int i = 0; i != 100; ++i) vector1[i].id = 100 - i - 1; sort(vector1.begin(), vector1.end(), not2(MyClass())); for (int k = 0; k != 100; ++k) cout << vector1[k].id << " "; return 0;
} /* 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56
57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 8
3 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 "
*/ </source>
Sort elements in deque
<source lang="cpp">
/* The following code example is taken from the book
* "The C++ Standard Library - A Tutorial and Reference" * by Nicolai M. Josuttis, Addison-Wesley, 1999 * * (C) Copyright Nicolai M. Josuttis 1999. * Permission to copy, use, modify, sell and distribute this software * is granted provided this copyright notice appears in all copies. * This software is provided "as is" without express or implied * warranty, and with no claim as to its suitability for any purpose. */
- include <iostream>
- include <vector>
- include <deque>
- include <list>
- include <set>
- include <map>
- include <string>
- include <algorithm>
- include <iterator>
- include <functional>
- include <numeric>
/* PRINT_ELEMENTS()
* - prints optional C-string optcstr followed by * - all elements of the collection coll * - separated by spaces */
template <class T> inline void PRINT_ELEMENTS (const T& coll, const char* optcstr="") {
typename T::const_iterator pos; std::cout << optcstr; for (pos=coll.begin(); pos!=coll.end(); ++pos) { std::cout << *pos << " "; } std::cout << std::endl;
} /* INSERT_ELEMENTS (collection, first, last)
* - fill values from first to last into the collection * - NOTE: NO half-open range */
template <class T> inline void INSERT_ELEMENTS (T& coll, int first, int last) {
for (int i=first; i<=last; ++i) { coll.insert(coll.end(),i); }
} using namespace std; int main() {
deque<int> coll; INSERT_ELEMENTS(coll,1,9); INSERT_ELEMENTS(coll,1,9); PRINT_ELEMENTS(coll,"on entry: "); // sort elements sort (coll.begin(), coll.end()); PRINT_ELEMENTS(coll,"sorted: ");
} /* on entry: 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 sorted: 1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9
*/ </source>
Sort elements reversely with custom function
<source lang="cpp">
/* The following code example is taken from the book
* "The C++ Standard Library - A Tutorial and Reference" * by Nicolai M. Josuttis, Addison-Wesley, 1999 * * (C) Copyright Nicolai M. Josuttis 1999. * Permission to copy, use, modify, sell and distribute this software * is granted provided this copyright notice appears in all copies. * This software is provided "as is" without express or implied * warranty, and with no claim as to its suitability for any purpose. */
- include <iostream>
- include <vector>
- include <deque>
- include <list>
- include <set>
- include <map>
- include <string>
- include <algorithm>
- include <iterator>
- include <functional>
- include <numeric>
/* PRINT_ELEMENTS()
* - prints optional C-string optcstr followed by * - all elements of the collection coll * - separated by spaces */
template <class T> inline void PRINT_ELEMENTS (const T& coll, const char* optcstr="") {
typename T::const_iterator pos; std::cout << optcstr; for (pos=coll.begin(); pos!=coll.end(); ++pos) { std::cout << *pos << " "; } std::cout << std::endl;
} /* INSERT_ELEMENTS (collection, first, last)
* - fill values from first to last into the collection * - NOTE: NO half-open range */
template <class T> inline void INSERT_ELEMENTS (T& coll, int first, int last) {
for (int i=first; i<=last; ++i) { coll.insert(coll.end(),i); }
} using namespace std; int main() {
deque<int> coll; INSERT_ELEMENTS(coll,1,9); INSERT_ELEMENTS(coll,1,9); PRINT_ELEMENTS(coll,"on entry: "); // sorted reverse sort (coll.begin(), coll.end(), // range greater<int>()); // sorting criterion PRINT_ELEMENTS(coll,"sorted >: ");
} /* on entry: 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 sorted >: 9 9 8 8 7 7 6 6 5 5 4 4 3 3 2 2 1 1
*/ </source>
Sorting user-defined class
<source lang="cpp">
- include <algorithm>
- include <functional>
- include <iostream>
- include <vector>
using namespace std; class MyClass {
public: MyClass( int num_points = 0 ); bool operator<( const MyClass& rhs ) const; int num_points() const; void print() const; private: vector<float> data_;
}; inline MyClass::MyClass( int num_points ): data_( num_points ){} inline bool MyClass::operator<( const MyClass& rhs ) const {
return num_points() < rhs.num_points();
} inline int MyClass::num_points() const {
return static_cast<int>( data_.size() );
} inline void MyClass::print() const{
cout << "\nThis experiment has " << num_points() << " data points";
} bool less_than_iterator( const vector<MyClass>::iterator i,const vector<MyClass>::iterator j ); // evaluate *i < *j int main( ) {
vector<MyClass> v; int num_v = 3; v.reserve( num_v ); v.push_back( MyClass( 3 ) ); v.push_back( MyClass( 9 ) ); v.push_back( MyClass( 5 ) ); for_each( v.begin(), v.end(),mem_fun_ref( &MyClass::print ) ); vector< vector<MyClass>::iterator > iterators( v.size() ); vector< vector<MyClass>::iterator >::iterator j = iterators.begin(); vector<MyClass>::iterator i = v.begin(); vector<MyClass>::iterator v_end = v.end(); while( i != v_end ) *j++ = i++; sort( iterators.begin(), iterators.end(), less_than_iterator ); vector< vector<MyClass>::iterator >::iterator iterators_end = iterators.end(); for( j = iterators.begin(); j != iterators_end; ++j ) (*j)->print(); for_each( v.begin(), v.end(), mem_fun_ref( &MyClass::print ) );
} bool less_than_iterator( const vector<MyClass>::iterator i,const vector<MyClass>::iterator j ) {
return *i < *j;
}
</source>
Sort into descending order by using greater
<source lang="cpp">
- include <cstdlib>
- include <iostream>
- include <vector>
- include <functional>
- include <algorithm>
using namespace std; void show(const char *msg, vector<int> vect); int main() {
vector<int> v(10); for(unsigned i=0; i < v.size(); i++) v[i] = rand() % 100; show("Original order:", v); sort(v.begin(), v.end(), greater<int>()); show("Order after sorting into descending order:", v); return 0;
} void show(const char *msg, vector<int> vect) {
cout << msg << endl; for(unsigned i=0; i < vect.size(); ++i) cout << vect[i] << endl;
}
</source>
Sort part of the elements in an array
<source lang="cpp">
/* The following code example is taken from the book
* "The C++ Standard Library - A Tutorial and Reference" * by Nicolai M. Josuttis, Addison-Wesley, 1999 * * (C) Copyright Nicolai M. Josuttis 1999. * Permission to copy, use, modify, sell and distribute this software * is granted provided this copyright notice appears in all copies. * This software is provided "as is" without express or implied * warranty, and with no claim as to its suitability for any purpose. */
- include <iostream>
- include <algorithm>
- include <functional>
- include <iterator>
using namespace std; int main() {
int coll[] = { 5, 6, 2, 4, 1, 3 }; // sort beginning with the second element sort (coll+3, coll+6); // print all elements copy (coll, coll+6,ostream_iterator<int>(cout," ")); cout << endl;
}
/*
5 6 2 1 3 4
*/ </source>
Sort random number
<source lang="cpp">
- include <iostream>
- include <algorithm>
using namespace std; const int N = 5; int main() {
int d[N], i, *e = d + N; for (i = 0; i < N; ++i){ d[i] = rand(); } sort(d, e); for (i = 0; i < N; ++i){ cout << d[i]; }
}
</source>
Sort the entire container
<source lang="cpp">
- include <cstdlib>
- include <iostream>
- include <vector>
- include <functional>
- include <algorithm>
using namespace std; void show(const char *msg, vector<int> vect); int main() {
vector<int> v(10); for(unsigned i=0; i < v.size(); i++) v[i] = rand() % 100; show("Original order:", v); sort(v.begin(), v.end()); show("Order after sorting into natural order:", v); return 0;
} void show(const char *msg, vector<int> vect) {
cout << msg << endl; for(unsigned i=0; i < vect.size(); ++i) cout << vect[i] << endl;
}
</source>
Use custom function and sort to sort strings by length
<source lang="cpp">
/* The following code example is taken from the book
* "The C++ Standard Library - A Tutorial and Reference" * by Nicolai M. Josuttis, Addison-Wesley, 1999 * * (C) Copyright Nicolai M. Josuttis 1999. * Permission to copy, use, modify, sell and distribute this software * is granted provided this copyright notice appears in all copies. * This software is provided "as is" without express or implied * warranty, and with no claim as to its suitability for any purpose. */
- include <iostream>
- include <vector>
- include <deque>
- include <list>
- include <set>
- include <map>
- include <string>
- include <algorithm>
- include <iterator>
- include <functional>
- include <numeric>
/* PRINT_ELEMENTS()
* - prints optional C-string optcstr followed by * - all elements of the collection coll * - separated by spaces */
template <class T> inline void PRINT_ELEMENTS (const T& coll, const char* optcstr="") {
typename T::const_iterator pos; std::cout << optcstr; for (pos=coll.begin(); pos!=coll.end(); ++pos) { std::cout << *pos << " "; } std::cout << std::endl;
} /* INSERT_ELEMENTS (collection, first, last)
* - fill values from first to last into the collection * - NOTE: NO half-open range */
template <class T> inline void INSERT_ELEMENTS (T& coll, int first, int last) {
for (int i=first; i<=last; ++i) { coll.insert(coll.end(),i); }
} using namespace std; bool lessLength (const string& s1, const string& s2) {
return s1.length() < s2.length();
} int main() {
vector<string> coll1; vector<string> coll2; // fill both collections with the same elements coll1.push_back ("1xxx"); coll1.push_back ("2x"); coll1.push_back ("3x"); coll1.push_back ("4x"); coll1.push_back ("5xx"); coll1.push_back ("6xxxx"); coll1.push_back ("7xx"); coll1.push_back ("8xxx"); coll1.push_back ("9xx"); coll1.push_back ("10xxx"); coll1.push_back ("11"); coll1.push_back ("12"); coll1.push_back ("13"); coll1.push_back ("14xx"); coll1.push_back ("15"); coll1.push_back ("16"); coll1.push_back ("17"); coll2 = coll1; PRINT_ELEMENTS(coll1,"on entry:\n "); // sort (according to the length of the strings) sort (coll1.begin(), coll1.end(), // range lessLength); // criterion stable_sort (coll2.begin(), coll2.end(), // range lessLength); // criterion PRINT_ELEMENTS(coll1,"\nwith sort():\n "); PRINT_ELEMENTS(coll2,"\nwith stable_sort():\n ");
}
/*
on entry:
1xxx 2x 3x 4x 5xx 6xxxx 7xx 8xxx 9xx 10xxx 11 12 13 14xx 15 16 17
with sort():
17 2x 3x 4x 16 15 13 12 11 9xx 7xx 5xx 8xxx 14xx 1xxx 10xxx 6xxxx
with stable_sort():
2x 3x 4x 11 12 13 15 16 17 5xx 7xx 9xx 1xxx 8xxx 14xx 6xxxx 10xxx */ </source>
Using an in-place generic sort algorithm
<source lang="cpp">
- include <iostream>
- include <algorithm>
- include <cassert>
using namespace std; int main() {
int a[1000]; int i; for (i = 0; i < 1000; ++i) a[i] = 1000 - i - 1; sort(&a[0], &a[1000]); for (i = 0; i < 1000; ++i) assert (a[i] == i); return 0;
}
</source>
Using the generic sort algorithm with a binary predicate: greater
<source lang="cpp">
- include <iostream>
- include <algorithm>
- include <cassert>
- include <functional>
using namespace std; int main() {
int a[100]; int i; for (i = 0; i < 100; ++i) a[i] = i; random_shuffle(&a[0], &a[100]); for (i = 0; i < 100; ++i) cout << a[i] << " "; cout <<"\n\n\n\n"; // Sort into descending order: sort(&a[0], &a[100], greater<int>());
for (i = 0; i < 100; ++i) cout << a[i] << " ";
return 0;
} /* 12 1 9 98 96 27 58 82 86 90 18 62 32 40 71 51 91 41 94 17 8 47 64 66 65 7 6 76 5
99 77 81 54 35 56 39 25 3 87 16 61 68 14 13 24 55 97 19 20 59 75 33 21 28 78 15 50 34 36 44 83 38 46 60 84 95 57 22 37 23 70 89 31 79 73 92 11 2 88 42 30 52 72 53 67 29 85 43 74 69 45 26 93 10 48 80 0 63 49 4
99 98 97 96 95 94 93 92 91 90 89 88 87 86 85 84 83 82 81 80 79 78 77 76 75 74 73
72 71 70 69 68 67 66 65 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 4
6 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 "
*/ </source>