//在两个数成对出现的数组中找到一个单独的数。比如{1，2，3。3，1，4。2}，即找出4

#include <stdio.h>

int find(int arr[], int len)

{

	int i = 0;

	int ret = 0;

	for (i = 0; i < len; i++)

	{

		ret = ret^arr[i];

	}

	return ret;

}

int main()

{

	int arr1[] = { 1, 2, 2, 3, 1, 5, 3 };

	int arr2[] = { 1, 2, 3,1,2,3,5,5,4,6,4 };

	printf("%d\n", find(arr1, sizeof(arr1) / sizeof(arr1[0])));

	printf("%d\n", find(arr2, sizeof(arr2) / sizeof(arr2[0])));

	return 0;

}

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