Watch 10 video solutions for Equal Row and Column Pairs, a medium level problem involving Array, Hash Table, Matrix. This walkthrough by Coding Decoded has 7,467 views views. Want to try solving it yourself? Practice on FleetCode or read the detailed text solution.
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].length1 <= n <= 2001 <= grid[i][j] <= 105