#include<stdio.h>
int tow_points(int arr[],int a,int sz)
{
int left=0;
int right=sz-1;
while(left<=right)
{
int mid=(left+right)/2;
if(arr[mid]<a)
{
left=mid+1;
}
if(arr[mid]>a)
{
right=mid-1;
}
if(arr[mid]==a)
{
return mid;
}
}
if(left>right)
return -1;
}
int main()
{
int arr[]={1,2,3,4,5,6,7,8,9};
int sz=sizeof(arr)/sizeof(arr[0]);
int a=8;
int b=tow_points (arr,a,sz);
if(-1==tow_points (arr,a,sz))
{
printf("该数组当中没有您要查询的数\n");
}
else
{
printf("该下标为：%d\n",b);
}
return 0;
}
