题目
题解
注意这里必须要求判断遇到的第一个重复的数字;
使用哈希来解
class Solution { public: // Parameters: // numbers: an array of integers // length: the length of array numbers // duplication: (Output) the duplicated number in the array number // Return value: true if the input is valid, and there are some duplications in the array number // otherwise false bool duplicate(int numbers[], int length, int* duplication) { vector<bool> f(length, false); for(int i = 0; i < length; i++) { if(!f[numbers[i]]) { f[numbers[i]] = true; }else{ duplication[0] = numbers[i]; return true; } } return false; } };