stupid bird learns 二分查找-优快云博客

本文链接：https://blog.youkuaiyun.com/m0_62722599/article/details/121592013

这篇博客介绍了两种C语言实现的查找算法：最普通查找和二分查找。在最普通查找中，遍历数组直到找到目标元素或结束。而在二分查找中，先对数组进行排序，然后通过不断缩小搜索范围来提高查找效率。博主还提供了代码示例，并展示了如何根据用户输入的数字进行查找操作。

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大佬们，家教stupid bird，它要哭了，代码要怎么改，才能使output_1正确运行？？？

最普通查找

#include<stdio.h>

int search(int key,int a[],int len)
{
	int ret = -1;
	for(int i=0;i<len;i++)
		{
			if(key==a[i])
				{
					ret = i+1;
					break;
				}
		}
	return ret;
}

int main()
{	int k;
	printf("please input the number you want:\n");
	scanf("%d",&k);
	int a[]={1,2,3,4,5,6,7,8,9}; 
	int r=search(k,a,sizeof(a)/sizeof(a[0]));
	if(r==-1)
		printf("the statistics is not here");
	else
		printf("%d is in the array and in the %d place",k,r);
		
	return 0;
	
	
}

二分查找

#include<stdio.h>

int search(int key,int a[],int len)
{
	int ret=-1;
	int left = 0;
	int right =len - 1;
	while(left<right)
		{	
			int mid = (left+right)/2;
			if(a[mid]==key)
				{	
					ret=mid + 1;
					break;
				}
			else if(a[mid]>key)
				right = mid - 1;
			else
				left = mid +1;
		}
	return ret;
}


int max(int a[],int len)
	{
		int maxid = 0;
		for(int i=1;i<len;i++)
			{
				if(a[i]>a[maxid])
					maxid = i;
			}
		return maxid;
	}

int main()
{	
	int n;
	printf("please input the amount of numbers you want(up to 100):\n");
	scanf("%d",&n);
	
	int m,a[100];
	
	printf("please input the unsorted numbers:\n");
	for(m=0;m<n;m++)
		scanf("%d",&a[m]);
		
	for(int i = n-1;i>0;i--)//选择排序 
		{
			int maxid = max(a,i+1);
			int t = a[maxid];
			a[maxid] = a[i];
			a[i] = t;
		} 
	printf("the follow is the sorted numbers:\n");
	for(int i = 0;i<n;i++)
		{
			printf("%d ",a[i]);
		}
	printf("\n");
		
	
	
	int k;
	printf("please input the number you want:\n");
	scanf("%d",&k); 
	
	int r=search(k,a,n);//二分查找 
	if(r==-1)
		printf("the statistics is not here");
	else
		printf("%d is in the array and in the %d place of the sorted numbers",k,r);
		
	return 0;
	
	
}

output_1

output_2