C/leetcode/src/704.c

int search(int* nums, int numsSize, int target){
    int low = 0, high = numsSize - 1;
    while (low <= high) {
        int mid = low + (high - low) / 2;
        if (target > nums[mid]) {
            low = mid + 1;
        } else if (target < nums[mid]) {
            high = mid - 1;
        } else {
            return mid;
        }
    }
    return -1;
}

/* Another solution: Using bsearch() */
int cmpint (const void *a, const void *b) {
    return *(int *) a - *(int *)b;
}

int search(int* nums, int numsSize, int target){
    int *ret = bsearch(&target, nums, numsSize, sizeof(int), cmpint);
    if (ret)
        return (ret - nums);
    else
        return -1;
}