Bitwise XOR of All Pairings

Leetcode Problem:

• Bitwise XOR of All Pairings

Summary

• Given two arrays, nums1 and nums2, return the bitwise XOR of all pairings of integers between nums1 and nums2.

Approach

• The solution uses two nested loops to iterate over the elements of nums1 and nums2
• For each element in nums1, it XORs the element with all elements in nums2
• Similarly, for each element in nums2, it XORs the element with all elements in nums1
• The XOR operation is used to combine the pairings, and the result is returned.

Complexity

• O(n*m) where n is the size of nums1 and m is the size of nums2

Explanation

• The solution iterates over the elements of nums1 and nums2 using two nested loops
• For each element in nums1, it XORs the element with all elements in nums2 using a single loop
• Similarly, for each element in nums2, it XORs the element with all elements in nums1 using another single loop
• The XOR operation is associative and commutative, so the order of the loops does not matter
• The result of the XOR operation is the bitwise XOR of all pairings of integers between nums1 and nums2.

Solution Code:

class Solution {
public:
    int xorAllNums(vector& nums1, vector& nums2) {
        int n1 = (nums1.size()-1) % 2;
        int n2 = (nums2.size()-1) % 2;
        int ans = 0;
        for(int i = 0 ; i < nums1.size(); i++){
            for(int j = 0 ; j <= n2; j++){
                ans ^= nums1[i];
            }
        }
        for(int i = 0 ; i < nums2.size(); i++){
            for(int j = 0; j <= n1; j++){
                ans ^= nums2[i];
            }
        }
        return ans;
    }
};