c语言之找单身狗

找单身狗1

#define  _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>
int find_dog(int arr[], int sz)
{
	int ret = 0;
	for (int i = 0; i < sz; i++)
	{
		ret ^= arr[i];
	}
	return ret;
}
int main()
{
	int arr[] = { 1,2,3,4,1,2,3 };
	int sz = sizeof(arr) / sizeof(arr[0]);
	int ret = find_dog(arr,sz);
	printf("%d", ret);
}

找单身狗2

void find_dog2(int arr[], int sz)
{
	//1、全部异或在一起
	int i = 0;
	int ret = 0;
	for (i = 0; i < sz; i++)
	{
		ret ^= arr[i];
	}
	//2、计算第几位为1
	int pos = 0;
	for (i = 0; i < 32; i++)//一个整型只有32位
	{
		if (((ret >> i) & 1) == 1)
		{
			pos = i;
			break;
		}
	}
	//3、分组
	int s1 = 0;
	int s2 = 0;
	for (i = 0; i < sz; i++)
	{
		if (((arr[i] >> pos) & 1 )== 1)
		{
			s1 ^= arr[i];
		}
		else
		{
			s2 ^= arr[i];
		}
	}
	printf("s1=%d ,s2=%d", s1, s2);
}
int main()
{
	int arr[] = { 1,2,3,4,5,1,2,3,4,6 };
	int sz = sizeof(arr) / sizeof(arr[0]);
     find_dog2(arr, sz);
	 return 0;
}