折半查找有序数组中的某个元素

define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
#include<stdlib.h>


int main()
{
int arr[] = { 1, 2, 3, 4, 5, 6, 8, 9, 10 };//数组是已排序的数组，有一定规律
int key=7 ;

int left = 0;
int right = sizeof(arr) / sizeof(arr[0]) - 1;
while (left <= right)
{
int mid = (left + right) / 2;//注意可能会溢出  left-(left-right)/2;
if (arr[mid] == key)
{
printf("找到啦
");
break;
}
else if (arr[mid] > key)
{
right = mid - 1;
}
else if (arr[mid] < key)
left = mid + 1;
}
if (left > right)
printf("没找到
");
system("pause
");
return 0;
}