#include <stdio.h>
#include <math.h>
void main()
{int high,low,m,k,a[10]={1,2,3,4,5,6,7,8,9,10};
scanf("%d",&k);
while (high>low)
{m=(high+low)/2;
if(k<m) high=m-1;
else if(k>m) low=m+1;
else m=(high+low)/2;}
printf("yes");
return;
if (k!=a[m])
{printf("no");
return;}
}
能运行,但是如果输入11不对。。。错哪了?