leetcode #136 single number

136 Single Number

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?

数组中，题目给定了一定至少存在一个数，所以不考虑特殊输入的情况

成对出现的数，要考虑使用^操作

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class  {
    public int singleNumber(int[] nums) {
        for(int i=1; i<nums.length; i++){
            nums[0] = nums[0]^nums[i];
        }
        return nums[0];
    }
}