In this guide, you will get 136. Single Number LeetCode Solution with the best time and space complexity. The solution to Single Number problem is provided in various programming languages like C++, Java, and Python. This will be helpful for you if you are preparing for placements, hackathons, interviews, or practice purposes. The solutions provided here are very easy to follow and include detailed explanations.
Given a non-empty array of integers nums, every element appears twice except for one. Find that single one.
You must implement a solution with a linear runtime complexity and use only constant extra space.
Example 1:
Input: nums = [2,2,1]
Output: 1
Example 2:
Input: nums = [4,1,2,1,2]
Output: 4
Example 3:
Input: nums = [1]
Output: 1
Constraints:
1 <= nums.length <= 3 * 104
-3 * 104 <= nums[i] <= 3 * 104
Each element in the array appears twice except for one element which appears only once.
Complexity Analysis
Time Complexity: O(n)
Space Complexity: O(1)
136. Single Number LeetCode Solution in C++
class Solution {
public:
int singleNumber(vector<int>& nums) {
int ans = 0;
for (const int num : nums)
ans ^= num;
return ans;
}
}; /* code provided by PROGIEZ */
136. Single Number LeetCode Solution in Java
class Solution {
public int singleNumber(int[] nums) {
int ans = 0;
for (final int num : nums)
ans ^= num;
return ans;
}
} // code provided by PROGIEZ
136. Single Number LeetCode Solution in Python
class Solution:
def singleNumber(self, nums: list[int]) -> int:
return functools.reduce(operator.xor, nums, 0) # code by PROGIEZ
