代码

int binary_search(const unsigned *a, int n, unsigned x)
{
        int h = n;
        int i = 2;
        n = h / 2;
        int j = 1;
        while(a[n] != x){
                i = i * 2;
                j  = j * 2;
                if(x > a[n])
                        j = j++;
                if(x < a[n])
                        j = j--;
                n = j * h / i;
        }
        return n;
}

评测结果