代码

int binary_search(const unsigned *a, int n, unsigned x)
{
	int b[2] = {0, n};
	do
	{
		int mid = (b[0] + b[1]) / 2;
		b[a[mid] > x] = mid;
	}
	while (b[0] + 1 != b[1]);
	return b[0];
}

评测结果