代码

int binary_search(const unsigned *a, int n, unsigned x)
{
	const unsigned *p = a;
	int mid;
	--n;
	while (p[n] != x)
		if (mid = (n * (long long)(x - *p) / (p[n] - *p)), p[mid] < x)
			p += mid + 1, n -= mid + 1;
		else
			n = mid;
	return p - a + n;
}

评测结果