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_s("%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;
}