第七章例7-6

#include<stdio.h>
int main(void)
{
 int a[10]={1,2,3,4,5,6,7,8,9,10};
 int low,high,mid,n=10,x;

 printf("Enter x: ");
 scanf("%d",&x);

 low=0;high=n-1;
 while(low<=high) {
  mid=(low+high)/2;
  if(x==a[mid])
     break;
  else if(x<a[mid])
   high=mid-1;
  else
   low=mid+1;
 }
 if(low<=high)
  printf("Index is %d ",mid);
 else
  printf("Not Found ");

 return 0;
}