二分查找

#include <stdio.h>
#include <stdlib.h>


int NBinarySearch(int a[],int x,int n)
{ int low = 0,high = n-1;
   while(low<=high)
   {
    int middle = (low+high)/2;
    if (x==a[middle]) return middle;
    else if (x>a[middle])  low=middle+1;
    else high=middle-1;
   }
    return -1;
}


int main()
 {
    int b[]={1,2,3,4,5,6,7,8,9,10};
    printf("%d\n",NBinarySearch(b,7,10));
    return 0;
 }