#include "s0036_valid_sudoku.hpp"

bool S0036::isValidSudoku(vector<vector<char>>& board) {
  vector<unordered_map<char, int>> rows;
  vector<unordered_map<char, int>> columns;
  vector<unordered_map<char, int>> grids;
  // Initialize vectors
  for (int i{0}; i < 9; ++i) {
    rows.push_back(unordered_map<char, int>{});
    columns.push_back(unordered_map<char, int>{});
    grids.push_back(unordered_map<char, int>{});
  }
  for (int i{0}; i < 9; ++i) {
    for (int j{0}; j < 9; ++j) {
      if (board[i][j] == '.') {
        continue;
      }
      if (rows[j].count(board[i][j]) == 1) {
        return false;
      } else {
        rows[j][board[i][j]] = 1;
      }
      if (columns[i].count(board[i][j]) == 1) {
        return false;
      } else {
        columns[i][board[i][j]] = 1;
      }
      int gridIndex =
          static_cast<int>(floor(j / 3)) + 3 * static_cast<int>(floor(i / 3));
      if (grids[gridIndex].count(board[i][j]) == 1) {
        return false;
      } else {
        grids[gridIndex][board[i][j]] = 1;
      }
    }
  }
  return true;
}