Leetcode 136. Single Number

算法 Java Leetcode

Find the single integer.

Question

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

Example: Given int[] arr = {1, 2, 1, 3, 4, 3, 2}, return 4.

Hint

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

Solution

• java
• cpp

public class Solution {
    public int singleNumber(int[] nums) {
        int result = 0;
        for (int i:nums){
            result ^= i;
        }
        return result;
    }
}

class Solution {
public:
    int singleNumber(vector<int>& nums) {
        int result = 0;
        for (int i = 0; i < nums.size(); i++) {
            result ^= nums[i];
        }
        return result;
    }
};