36 - Valid Sudoku

 JAVA

• class Solution {
      public boolean isValidSudoku(char[][] board) {
          boolean[][] row = new boolean[9][9];
          boolean[][] col = new boolean[9][9];
          boolean[][] sub = new boolean[9][9];
          for (int i = 0; i < 9; ++i) {
              for (int j = 0; j < 9; ++j) {
                  char c = board[i][j];
                  if (c == '.') {
                      continue;
                  }
                  int num = c - '0' - 1;
                  int k = i / 3 * 3 + j / 3;
                  if (row[i][num] || col[j][num] || sub[k][num]) {
                      return false;
                  }
                  row[i][num] = true;
                  col[j][num] = true;
                  sub[k][num] = true;
              }
          }
          return true;
      }
  }

C++

• class Solution {
  public:
      bool isValidSudoku(vector<vector<char>>& board) {
          vector<vector<bool>> row(9, vector<bool>(9, false));
          vector<vector<bool>> col(9, vector<bool>(9, false));
          vector<vector<bool>> sub(9, vector<bool>(9, false));
          for (int i = 0; i < 9; ++i) {
              for (int j = 0; j < 9; ++j) {
                  char c = board[i][j];
                  if (c == '.') continue;
                  int num = c - '0' - 1;
                  int k = i / 3 * 3 + j / 3;
                  if (row[i][num] || col[j][num] || sub[k][num]) {
                      return false;
                  }
                  row[i][num] = true;
                  col[j][num] = true;
                  sub[k][num] = true;
              }
          }
          return true;
      }
  };