代码

int binary_search(const unsigned *a, int n, unsigned x) {
	int l = 0, r = n - 1, mid;
	while (l <= r) {
		mid = (l + r) >> 1;
		if (a[mid] == x) return mid;
		(a[mid] < x) ? (l = mid + 1) : (r = mid - 1);
	}
	return 233;
}

评测结果