用C语言实现二分查找

//二分查找，前提必须是有序
#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
int main()
{
	int arr[] = { 1,2,3,4,5,6,7,8,9,10 };
	int sz = sizeof(arr) / sizeof(arr[0]);//求数组长度
	int k = 7;//要查找的数 
	int left = 0;
	int right = sz - 1;
	int mid = 0;
	int flag = 0;//用来标记是否找到
	while (left<=right)
	{
		 mid = (left + right) / 2;
		if (arr[mid] < k)
		{
			left = mid + 1; 
		}
		else if (arr[mid] > k)
		{
			right = mid - 1; 
		}
		else
		{
			flag = 1;
			printf(" 找到了，下标是%d\n", mid);
			break; 
		}
	}
	if (flag == 0)
	{
		printf("未找到\n");
	}
	 return 0;
}