c++中如何自定义排序规则_c++ sort函数自定义比较函数方法

#include <algorithm>
#include <vector>
#include <iostream>
<p>bool cmp(int a, int b) {
return a > b;  // 降序
}</p><p>int main() {
std::vector<int> vec = {3, 1, 4, 1, 5};
std::sort(vec.begin(), vec.end(), cmp);</p><pre class='brush:php;toolbar:false;'>for (int x : vec) std::cout << x << " ";
// 输出：5 4 3 1 1
return 0;

std::sort(vec.begin(), vec.end(), [](int a, int b) {
    return a > b;
});

int target = 5;
std::sort(vec.begin(), vec.end(), [target](int a, int b) {
    return abs(a - target) < abs(b - target);
});

struct Student {
    std::string name;
    int score;
};
<p>std::vector<Student> students = {{"Alice", 85}, {"Bob", 90}, {"Charlie", 85}};</p><p>std::sort(students.begin(), students.end(), [](const Student& a, const Student& b) {
if (a.score != b.score)
return a.score > b.score;  // 成绩高者优先
return a.name < b.name;        // 成绩相同按名字升序
});</p>

struct Greater {
    bool operator()(int a, int b) {
        return a > b;
    }
};
<p>std::sort(vec.begin(), vec.end(), Greater());</p>