Array Hash Map Counting
Intermediate Level

Implement the validSudokuRowsSimple method that checks whether each row of a Sudoku board is valid.

The input contains a character matrix board and its size n. Your task is to check whether each row is valid.

For this simplified Sudoku-style problem, a row is valid when it does not contain the same non-empty value more than once in that row.

For example, the row [1,2,3] is valid, but [1,1,3] is invalid because 1 appears twice in the same row.

Example 1
Input:
board (char[][]) = [[1,2,3],[4,5,6],[7,8,9]]
n (int) = 3
Return:
(boolean) true
Example 2
Input:
board (char[][]) = [[1,2,3],[1,5,6],[7,8,9]]
n (int) = 3
Return:
(boolean) true
Example 3
Input:
board (char[][]) = [[1,1,3],[4,5,6],[7,8,9]]
n (int) = 3
Return:
(boolean) false

Check each row separately using a set.

For every row, clear the set before scanning its cells. If a value already exists in the set, that row contains a duplicate and the board fails the row validation.

If all rows are scanned without finding a duplicate, return true.

Pseudocode:

function validSudokuRowsSimple(board, n):
    for r from 0 to n - 1:
        create empty set seen
        for c from 0 to n - 1:
            value = board[r][c]
            if value exists in seen:
                return false
            add value to seen
    return true
Run your code to see the result.