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\n",mid);
else
  printf("Not Found\n");