Single Number Problem
Description
LeetCode Problem 136.
Given a non-emptyarray of integers nums, every element appears twice except for one. Find that single one.
You mustimplement a solution with a linear runtime complexity and useonly constantextra space.
Example 1:
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Input: nums = [2,2,1]
Output: 1
Example 2:
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Input: nums = [4,1,2,1,2]
Output: 4
Example 3:
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Input: nums = [1]
Output: 1
Constraints:
- 1 <= nums.length <= 3 * 10^4
- -3 * 10^4 <= nums[i] <= 3 * 10^4
- Each element in the array appears twice except for one element which appears only once.
Sample C++ Code
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class Solution {
public:
int singleNumber(vector<int>& nums) {
int n = 0;
for (int i = 0; i < nums.size(); i ++) {
n = n ^ (nums[i]);
}
return n;
}
};