LeetCode题解之 Find the Town Judge

1、题目描述

2、问题分析

使用map set数据结构。

3、代码

 int findJudge(int N, vector<vector<int>>& trust) {
        
        if (trust.size() == 0)
            return 1;
        
        int n = 0;
        map<int, int> m;
        set<int> s;
        for (auto it = trust.begin(); it != trust.end(); it++) {
            m[(*it).back()]++;
            s.insert((*it).front());
        }
        
        int peo = INT_MIN;
        for (auto it = m.begin(); it != m.end(); it++) {
            if (it->second > n){
                n = it->second;
                peo = it->first;
            }
        }
        
        return ((n == (N - 1)) && s.find(peo) == s.end()) ? peo : -1;
        
    }