题解 | #数组中重复的数字#

利用数组元素都在0~n-1的性质，记录已经出现过的数

class Solution {
public:
    bool duplicate(int numbers[], int length, int* duplication) {
        for (int i = 0; i < length; i++) {
            int index = numbers[i] % length;
            if (numbers[index] >= length) {
                *duplication = index;
                return true;
            }
            numbers[index] += length;
        }
        return false;
    }
};