C++ Tutorial/STL Algorithms Sorting/sort — различия между версиями
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Текущая версия на 13:30, 25 мая 2010
Содержание
- 1 Sort all element in an array
- 2 Sort a vector and print out the sorted elements
- 3 Sort a vector into ascending order of id members
- 4 Sort elements in deque
- 5 Sort elements reversely with custom function
- 6 Sort part of the elements in an array
- 7 Use custom function and sort to sort strings by length
- 8 Using an in-place generic sort algorithm
- 9 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;
}</source>
1 2 3 4 5 6
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 << " "; }
}</source>
1 2 3 4 5 6
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;
}</source>
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 "
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: ");
}</source>
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
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 >: ");
}</source>
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
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;
}</source>
5 6 2 1 3 4
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 ");
}</source>
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
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;
}</source>
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