哪家公司做企业网站稳定优惠,最新网站制作,有域名可以自己做网站吗,网站登录账号密码保存algorithm此头文件是算法库的一部分。本篇介绍不修改序列的操作函数。 不修改序列的操作 all_ofany_ofnone_of (C11)(C11)(C11) 检查谓词是否对范围中所有、任一或无元素为 true (函数模板) for_each 应用函数到范围中的元素 (函数模板) for_each_n (C17) 应用一个函数对象到序…algorithm此头文件是算法库的一部分。本篇介绍不修改序列的操作函数。 不修改序列的操作 all_ofany_ofnone_of (C11)(C11)(C11) 检查谓词是否对范围中所有、任一或无元素为 true (函数模板) for_each 应用函数到范围中的元素 (函数模板) for_each_n (C17) 应用一个函数对象到序列的前 n 个元素 (函数模板) countcount_if 返回满足指定判别标准的元素数 (函数模板) mismatch 寻找两个范围出现不同的首个位置 (函数模板) findfind_iffind_if_not (C11) 寻找首个满足特定判别标准的元素 (函数模板) find_end 在特定范围中寻找最后出现的元素序列 (函数模板) find_first_of 搜索元素集合中的任意元素 (函数模板) adjacent_find 查找首对相邻的相同或满足给定谓词的元素 (函数模板) search 搜索一个元素范围 (函数模板) search_n 在范围中搜索一定量的某个元素的连续副本 (函数模板)
示例代码
#include algorithm
#include functional
#include iostream
#include iterator
#include utility // std::pair
#include vector
#include array
#include cctype // std::tolowervoid myfunction(int i) { // function:std::cout i;
}struct myclass { // function object type:void operator() (int i) { std::cout i; }
} myobject;bool IsOdd(int i) { return ((i % 2) 1); }bool mypredicate(int i, int j) {return (i j);
}bool myfunction8(int i, int j) {return (i j);
}bool comp_case_insensitive9(char c1, char c2) {return (std::tolower(c1) std::tolower(c2));
}bool myfunction10(int i, int j) {return (i j);
}bool mypredicate11(int i, int j) {return (i j);
}bool mypredicate12(int i, int j) {return (i j);
}int main()
{// all_of example 检查谓词是否对范围中所有、任一或无元素为 truestd::arrayint, 8 foo { 3,5,7,11,13,17,19,23 };if (std::all_of(foo.begin(), foo.end(), [](int i) {return i % 2; }))std::cout All the elements are odd numbers.\n;// any_of examplestd::arrayint, 7 foo2 { 0,1,-1,3,-3,5,-5 };if (std::any_of(foo2.begin(), foo2.end(), [](int i) {return i 0; }))std::cout There are negative elements in the range.\n;// none_of examplestd::arrayint, 8 foo3 { 1,2,4,8,16,32,64,128 };if (std::none_of(foo3.begin(), foo3.end(), [](int i) {return i 0; }))std::cout There are no negative elements in the range.\n;// for_each example 应用函数到范围中的元素 std::vectorint myvector;myvector.push_back(10);myvector.push_back(20);myvector.push_back(30);std::cout myvector contains:;for_each(myvector.begin(), myvector.end(), myfunction);std::cout \n;// or:std::cout myvector contains:;for_each(myvector.begin(), myvector.end(), myobject);std::cout \n;// count algorithm example 返回满足指定判别标准的元素数 // counting elements in array:int myints[] { 10,20,30,30,20,10,10,20,10,20 }; // 8 elementsint mycount std::count(myints, myints 8, 10);std::cout 10 appears mycount times.\n;// counting elements in container:std::vectorint myvector2(myints, myints 10);mycount std::count(myvector2.begin(), myvector2.end(), 20);std::cout 20 appears mycount times.\n;// count_if examplestd::vectorint myvector3;for (int i 1; i 10; i) myvector3.push_back(i); // myvector: 1 2 3 4 5 6 7 8 9int mycount3 count_if(myvector3.begin(), myvector3.end(), IsOdd);std::cout myvector3 contains mycount3 odd values.\n;// mismatch algorithm example 寻找两个范围出现不同的首个位置 std::vectorint myvector4;for (int i 1; i 6; i) myvector4.push_back(i * 10); // myvector4: 10 20 30 40 50int myints4[] { 10,20,80,320,1024 }; // myints4: 10 20 80 320 1024std::pairstd::vectorint::iterator, int* mypair4;// using default comparison:mypair4 std::mismatch(myvector4.begin(), myvector4.end(), myints4);std::cout First mismatching elements: *mypair4.first;std::cout and *mypair4.second \n;mypair4.first; mypair4.second;// using predicate comparison:mypair4 std::mismatch(mypair4.first, myvector4.end(), mypair4.second, mypredicate);std::cout Second mismatching elements: *mypair4.first;std::cout and *mypair4.second \n;// find example// using std::find with array and pointer:int myints5[] { 10, 20, 30, 40 };int *p;p std::find(myints5, myints5 4, 30);if (p ! myints5 4)std::cout Element found in myints5: *p \n;elsestd::cout Element not found in myints5\n;// using std::find with vector and iterator:std::vectorint myvector5(myints5, myints5 4);std::vectorint::iterator it;it find(myvector5.begin(), myvector5.end(), 30);if (it ! myvector5.end())std::cout Element found in myvector5: *it \n;elsestd::cout Element not found in myvector5\n;// find_if examplestd::vectorint myvector6;myvector6.push_back(10);myvector6.push_back(25);myvector6.push_back(40);myvector6.push_back(55);std::vectorint::iterator it6 std::find_if(myvector6.begin(), myvector6.end(), IsOdd);std::cout The first odd value is *it6 \n;// find_if_not examplestd::arrayint, 5 foo7 { 1,2,3,4,5 };std::arrayint, 5::iterator it7 std::find_if_not(foo7.begin(), foo7.end(), [](int i) {return i % 2; });std::cout The first even value is *it7 \n;// find_end exampleint myints8[] { 1,2,3,4,5,1,2,3,4,5 };std::vectorint haystack8(myints8, myints8 10);int needle1[] { 1,2,3 };// using default comparison:std::vectorint::iterator it8;it8 std::find_end(haystack8.begin(), haystack8.end(), needle1, needle1 3);if (it8 ! haystack8.end())std::cout needle1 last found at position (it8 - haystack8.begin()) \n;int needle2[] { 4,5,1 };// using predicate comparison:it8 std::find_end(haystack8.begin(), haystack8.end(), needle2, needle2 3, myfunction8);if (it8 ! haystack8.end())std::cout needle2 last found at position (it8 - haystack8.begin()) \n;// find_first_of exampleint mychars9[] { a,b,c,A,B,C };std::vectorchar haystack9(mychars9, mychars9 6);std::vectorchar::iterator it9;int needle9[] { A,B,C };// using default comparison:it9 find_first_of(haystack9.begin(), haystack9.end(), needle9, needle9 3);if (it9 ! haystack9.end())std::cout The first match is: *it9 \n;// using predicate comparison:it9 find_first_of(haystack9.begin(), haystack9.end(),needle9, needle9 3, comp_case_insensitive9);if (it9 ! haystack9.end())std::cout The first match is: *it9 \n;// adjacent_find exampleint myints10[] { 5,20,5,30,30,20,10,10,20 };std::vectorint myvector10(myints10, myints10 8);std::vectorint::iterator it10;// using default comparison:it10 std::adjacent_find(myvector10.begin(), myvector10.end());if (it10 ! myvector10.end())std::cout the first pair of repeated elements are: *it10 \n;//using predicate comparison:it10 std::adjacent_find(it10, myvector10.end(), myfunction10);if (it10 ! myvector10.end())std::cout the second pair of repeated elements are: *it10 \n;// search algorithm examplestd::vectorint haystack11;// set some values: haystack11: 10 20 30 40 50 60 70 80 90for (int i 1; i 10; i) haystack11.push_back(i * 10);// using default comparison:int needle11[] { 40,50,60,70 };std::vectorint::iterator it11;it11 std::search(haystack11.begin(), haystack11.end(), needle11, needle11 4);if (it11 ! haystack11.end())std::cout needle11 found at position (it11 - haystack11.begin()) \n;elsestd::cout needle11 not found\n;// using predicate comparison:int needle21[] { 20,30,50 };it11 std::search(haystack11.begin(), haystack11.end(), needle21, needle21 3, mypredicate11);if (it11 ! haystack11.end())std::cout needle21 found at position (it11 - haystack11.begin()) \n;elsestd::cout needle21 not found\n;// search_n exampleint myints12[] { 10,20,30,30,20,10,10,20 };std::vectorint myvector12(myints12, myints12 8);std::vectorint::iterator it12;// using default comparison:it12 std::search_n(myvector12.begin(), myvector12.end(), 2, 30);if (it12 ! myvector12.end())std::cout two 30s found at position (it12 - myvector12.begin()) \n;elsestd::cout match not found\n;// using predicate comparison:it12 std::search_n(myvector12.begin(), myvector12.end(), 2, 10, mypredicate12);if (it12 ! myvector12.end())std::cout two 10s found at position int(it12 - myvector12.begin()) \n;elsestd::cout match not found\n;std::cout hello world\n;return 0;
}
运行结果 参考
https://cplusplus.com/reference/algorithm/
https://zh.cppreference.com/w/cpp/header/algorithm
