3158. Find the XOR of Numbers Which Appear Twice LeetCode Solution
In this guide, you will get 3158. Find the XOR of Numbers Which Appear Twice LeetCode Solution with the best time and space complexity. The solution to Find the XOR of Numbers Which Appear Twice 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.
Problem Statement of Find the XOR of Numbers Which Appear Twice
You are given an array nums, where each number in the array appears either once or twice.
Return the bitwise XOR of all the numbers that appear twice in the array, or 0 if no number appears twice.
Example 1:
Input: nums = [1,2,1,3]
Output: 1
Explanation:
The only number that appears twice in nums is 1.
Example 2:
Input: nums = [1,2,3]
Output: 0
Explanation:
No number appears twice in nums.
Example 3:
Input: nums = [1,2,2,1]
Output: 3
Explanation:
Numbers 1 and 2 appeared twice. 1 XOR 2 == 3.
Constraints:
1 <= nums.length <= 50
1 <= nums[i] <= 50
Each number in nums appears either once or twice.
Complexity Analysis
Time Complexity: O(n)
Space Complexity: O(50) = O(1)
3158. Find the XOR of Numbers Which Appear Twice LeetCode Solution in C++
class Solution {
public:
int duplicateNumbersXOR(vector<int>& nums) {
constexpr int kMax = 50;
int ans = 0;
vector<int> count(kMax + 1);
for (const int num : nums)
++count[num];
for (int num = 1; num <= kMax; ++num)
if (count[num] == 2)
ans ^= num;
return ans;
}
}; /* code provided by PROGIEZ */
3158. Find the XOR of Numbers Which Appear Twice LeetCode Solution in Java
class Solution {
public int duplicateNumbersXOR(int[] nums) {
final int kMax = 50;
int ans = 0;
int[] count = new int[kMax + 1];
for (final int num : nums)
++count[num];
for (int num = 1; num <= kMax; ++num)
if (count[num] == 2)
ans ^= num;
return ans;
}
} // code provided by PROGIEZ
3158. Find the XOR of Numbers Which Appear Twice LeetCode Solution in Python
class Solution:
def duplicateNumbersXOR(self, nums):
count = collections.Counter(nums)
return functools.reduce(
operator.xor, [num for num, freq in count.items() if freq == 2],
) # code by PROGIEZ
