Leetcode 2352 Equal Row and Column Pairs Solution in CPP | Hindi Coding Community

 

Given a 0-indexed n x n integer matrix grid, return the number of pairs (Ri, Cj) such that row Ri and column Cj are equal.

A row and column pair is considered equal if they contain the same elements in the same order (i.e. an equal array).

 

Example 1:

Input: grid = [[3,2,1],[1,7,6],[2,7,7]]
Output: 1
Explanation: There is 1 equal row and column pair:
- (Row 2, Column 1): [2,7,7]

Example 2:

Input: grid = [[3,1,2,2],[1,4,4,5],[2,4,2,2],[2,4,2,2]]
Output: 3
Explanation: There are 3 equal row and column pairs:
- (Row 0, Column 0): [3,1,2,2]
- (Row 2, Column 2): [2,4,2,2]
- (Row 3, Column 2): [2,4,2,2]

 

Constraints:

• n == grid.length == grid[i].length
• 1 <= n <= 200
• 1 <= grid[i][j] <= 105

CPP Code :

class Solution {

public:

int equalPairs(vector<vector<int>>& grid)

{

int ans = 0;

map<vector<int>, int> mp;

for (int i = 0; i < grid.size(); i++)

mp[grid[i]]++;

for (int i = 0; i < grid[0].size(); i++)

{

vector<int> v;

for (int j = 0; j < grid.size(); j++)

v.push_back(grid[j][i]);

ans += mp[v];

}

return ans;

}

};