#include
void main()
{
int a[15]={15,14,13,12,11,10,9,8,7,6,5,4,3,2,1};
int i,left=0,right=14,flag=0,d,mid;
printf("输入数值:");
scanf("%d",&d);
if(d < a[14]||d >a[0])
{ printf("\nchon gxin:");
scanf("%d",&d);}
for(i=1;i <5;i++) //16个最多比较4次
{
mid=(left+right)/2;
if(d==a[mid])
{
printf("第 %d 个.\n",mid);
flag=1;break;
}
else if(d>a[mid])
right=mid-1;
else left=mid+1;
}
if(flag==0) printf("无效.\n");
}
呵呵
我写过这类的,还在吗》哥们