《leetCode》：Single Number

题目

Given an array of integers, every element appears twice except for one. Find that single one.

Note:
Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory?

思路

int singleNumber(int* nums, int numsSize) {
if(nums==NULL||numsSize<1){
return 0;
}
int xorValue=nums[0];
for(int i=1;i<numsSize;i++){
xorValue^=nums[i];
}
return xorValue;
}