根据pair 排序

1. 描述

// vector<pair> 排序
// [1, 2] [1, 3] [2, 3] [2, 4]
// [1, 3] [1, 2] [2, 4] [2, 3]

2. 代码

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

using namespace std;

bool cmp(const pair<int, int> a, const pair<int, int> b){
    
    

    if(a.first == b.first){
    
    
        return a.second > b.second;
    }else{
    
    
        return a.first < b.first;
    }
}

int main(){
    
    
    vector<pair<int, int> > vec;
    vec.push_back(make_pair(1, 2));
    vec.push_back(make_pair(1, 3));
    vec.push_back(make_pair(2, 3));
    vec.push_back(make_pair(2, 4));

    sort(vec.begin(), vec.end(), cmp);

    for(auto num: vec){
    
    
        cout << num.first << "," << num.second << endl;
    }
}