//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;
}
<img src="//img-blog.csdn.net/20150630154614683?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQvZG91ZG91d2ExMjM0/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center" alt="" />
