C语言练习——找单身狗问题

题目描述

• 找单身狗问题：
• 1.现有一个数组，只有一个元素只出现了一次，其它元素都出现了两次，请找出这个元素。
• 2.如果数组中，有两个元素只出现了一次，其他元素都出现了两次，请找出这两个元素。

代码实现

#include 
#include 

int FindOneSingleDog(int arr[], int size)
{
	int Dog = arr[0];
	for (int i = 0; i < size; i++)
	{
		Dog = Dog ^ arr[i];
	}
	return Dog;
}

int FindTwoSingleDog(int arr[], int size, int* Dog1, int* Dog2)
{
	int rst = arr[0];
	int leftPos = 0;

	for (int i = 1; i < size; i++)
	{
		rst = rst ^ arr[i];
	}
	for (leftPos = 0; leftPos < 32; leftPos++)
	{
		if ((rst & (1 << leftPos)) == 1)
		{
			break;
		}
	}

	*Dog1 = 0;
	*Dog2 = 0;

	for (int i = 0; i < size; i++)
	{
		if ((arr[i] & (1 << leftPos)) == 1)
		{
			*Dog1 = *Dog1 ^ arr[i];
		}
		else
		{
			*Dog2 = *Dog2 ^ arr[i];
		}
	}
	return 0;
}

int main()
{
	int arr1[] = { 1,2,3,3,2,1,4 };
	int size1 = sizeof(arr1) / sizeof(arr1[0]);
	int Dog{};

	int arr2[] = { 1,1,2,2,3,3,4,5 };
	int size2 = sizeof(arr2) / sizeof(arr2[0]);
	int Dog1{}, Dog2{};

	Dog = FindOneSingleDog(arr1, size1);
	printf("The One Single Dog Is: %d.\n", Dog);

	FindTwoSingleDog(arr2, size2, &Dog1, &Dog2);
	printf("The Two Single Dog Is: %d And %d.\n", Dog1, Dog2);

	system("pause");
	return 0;
}

调试结果