题解 | #数组中重复的数字#

class Solution {
public:
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param numbers int整型vector 
     * @return int整型
     */
    int duplicate(vector<int>& numbers) {
        // write code here
        map<int, int> mymap;
        for (int i = 0; i < numbers.size(); i++) {
            if (numbers[i] > numbers.size()-1) return -1;
            mymap[numbers[i]]++;
        }
        map<int, int>::iterator it;
        for (it = mymap.begin(); it != mymap.end(); it++)
            if (it->second > 1) 
                return it->first;
        return 1;
    }
};