c++中怎么对vector进行排序_c++ vector排序实用方法汇总

#include <vector>
#include <algorithm>
#include <iostream>

int main() {
    std::vector<int> vec = {5, 2, 8, 1, 9};

    std::sort(vec.begin(), vec.end());

    for (int x : vec) {
        std::cout << x << " ";
    }
    // 输出：1 2 5 8 9
    return 0;
}

std::sort(vec.begin(), vec.end(), std::greater<int>());

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

struct Student {
    std::string name;
    int score;
};

std::vector<Student> students = {{"Alice", 85}, {"Bob", 90}, {"Charlie", 70}};

// 按分数从高到低排序
std::sort(students.begin(), students.end(), [](const Student& a, const Student& b) {
    return a.score > b.score;
});

std::sort(students.begin(), students.end(), [](const Student& a, const Student& b) {
    return a.name < b.name;
});

std::sort(students.begin(), students.end(), [](const Student& a, const Student& b) {
    if (a.score != b.score) {
        return a.score > b.score;  // 成绩高的在前
    }
    return a.name < b.name;       // 成绩相同则名字字典序小的在前
});

// 只对前5个元素排序
std::sort(vec.begin(), vec.begin() + 5);

bool compareDescending(int a, int b) {
    return a > b;
}

std::sort(vec.begin(), vec.end(), compareDescending);