【C】折半查找法

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

void main()
{
	int arr[] = { 1,3,5,7,9,11,13,15,17,19 };
	int key=0,mid=0, left = 0, right = sizeof(arr) / 4 - 1;
	printf("请输入哟个要查找的数字：");
	scanf("%d", &key);
	for (left = 0; left <=right; )
	{
		mid = (left + right) / 2; 
		if (key>arr[mid])
		{
			left = mid+1;
		}
		else if (key < arr[mid])
		{
			right = mid-1;
		}
		else
		{
			break;
		}
	}	
	if(left<=right)
		printf("找到了\n"); 
	else
	{
		printf("没找到\n");
	}
	system("pause");
}