【leetcode】最短无序连续子数组

int Mycmp(const void* a, const void* b)
{
    return *(int*)a  - *(int*)b;
}
int findUnsortedSubarray(int* nums, int numsSize){
    int* arr = (int*)calloc(numsSize, sizeof(int));
    memcpy(arr, nums, numsSize*sizeof(int));
    qsort(arr, numsSize, sizeof(int), Mycmp);
    int head = -1;
    int tail = numsSize;
    for (int i = 0; i < numsSize; i++)
    {
        if (head == -1 && nums[i] != arr[i])head = i;
        if (tail == numsSize && nums[numsSize - 1 - i] != arr[numsSize - 1 - i])tail = numsSize - 1 - i;
        if (head != -1 && tail != numsSize) return tail-head+1;
    }
    return 0;
}