LeetCode Contains Duplicate

LeetCode Contains Duplicate

题目

思路

刚开始还以为是什么异或判重；
后来发现是自己想错了- -；
还是哈希好点。

代码

bool containsDuplicate(int* nums, int numsSize) {
    if (numsSize <= 1) return false;
    int length = 100007;
    if (numsSize < length) length = numsSize;
    int * hash = (int*)malloc(sizeof(int) * length);
    bool * used = (bool*)malloc(sizeof(bool) * length);
    for (int i = 0; i < length; i++) used[i] = false;
    for (int i = 0; i < numsSize; i++) {
        int p = (nums[i] + numsSize) % numsSize;
        while (used[p]) {
            if (hash[p] == nums[i]) {
                free(hash);
                free(used);
                return true;
            }
            p++;
            if (p == length) p = 0;
        }
        hash[p] = nums[i];
        used[p] = true;
    }
    free(hash);
    free(used);
    return false;
}