c++ std::sort函数是经常被使用到的,但是不知道大家注意没有,定义的Compare函数是需要满足一定条件的。这个条件就是:strict weak ordering。 cppreference的英文原文: comparison function object (i.e. an object that satisfies the requirements ofCompare
https://en.cppreference.com/w/cpp/named_req/Compare中写道: 严格是说在判断的时候会用"<",而不是"<=" 1、sort的简单应用: sort - C++ Reference (cplusplus.com) //sort algorithm example#include <iostream>//std::cout#include <algorithm>//std::sort#include <vector>//std::vectorboolmyfunctio...
("sorted with the standard library compare function object");struct{booloperator()(inta,intb)const{returnab;});print("sorted with a lambda expression");} Output: 0 1 2 3 4 5 6 7 8 9 : sorted with the default operator< 9 8 7 6 5 4 3 2 1 0 : sorted with the standard librar...
std::cout #include <algorithm> // std::sort #include <vector> // std::vector using namespace std; bool myfunction (int i,int j) { return (i>j); } int main () { vector<int> myvector = {32,71,12,45,26,80,53,33}; // using function as comp sort (my...
// sort using a custom function object struct { bool operator()(int a, int b) { return a < b; } } customLess; std::sort(s.begin(), s.end(), customLess); for (int a : s) { std::cout << a << " "; } std::cout << '\n'; ...
当我们使用std::sort的时,如果提供了比较函数,要注意比较函数需要满足一定条件,否则可能会引发crash。 错误范例: #include <algorithm> #include <string> #include <vector> #include <iostream> using namespace std; bool cmp(const string& s1, const string& s2) ...
// sort using a custom function object struct { bool operator()(int a, int b) { return a < b; } } customLess; std::sort(s.begin(), s.end(), customLess); for (int a : s) { std::cout << a << " "; } std::cout << '\n'; ...
2,4)同(1,3),但按照policy执行。这些重载仅若std::is_execution_policy_v<std::decay_t<ExecutionPolicy>>(C++20 前)std::is_execution_policy_v<std::remove_cvref_t<ExecutionPolicy>>(C++20 起)为 true 才参与重载决议。 参数 first, last-要排序的元素范围 ...
comp-comparison function object (i.e. an object that satisfies the requirements ofCompare) which returns trueif the first argument islessthan (i.e. is orderedbefore) the second. The signature of the comparison function should be equivalent to the following: ...
2)At most2N⋅log(N)applications of the comparison functioncomp. Possible implementation sort_heap (1) template<classRandomIt>voidsort_heap(RandomIt first, RandomIt last){while(first!=last)std::pop_heap(first, last--);} sort_heap (2) ...