136. Single Number (Easy)
https://leetcode.com/problems/single-number/
Given a non-empty 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?
Example 1:
Input: [2,2,1] Output: 1
Example 2:
Input: [4,1,2,1,2] Output: 4
Solutions
class Solution {
public int singleNumber(int[] nums) {
// a ^ b ^ c = a ^ c ^ b = b ^ a ^ c
int x = 0;
for (int a : nums) {
x = x ^ a;
}
return x;
}
}
Incorrect Solutions
References
https://www.programcreek.com/2012/12/leetcode-solution-of-single-number-in-java/