代码

int binary_search(const unsigned *a, int n, unsigned x)
{
    const unsigned int *p=a+(((unsigned long long)x*100000000)>>32)-0x2c00;
    //printf("d=%u x=%u\n",x,d);
    for(int i=0x4000;;i>>=1)
    {
        //printf("p=0x%x a=0x%x p-a=0x%x i=0x%x p+i-a=0x%x\n",p,a,p-a,i,p-a+i);
        if(p[i]<=x)p+=i;
        if(i==0)return p-a;
    }
}

评测结果