723. Candy Crush

https://leetcode.com/problems/candy-crush/

Python

class Solution:
    def candyCrush(self, board: List[List[int]]) -> List[List[int]]:
        while self.crash(board):
            self.drop(board)

        return board

    def crash(self, board) -> bool:
        m = len(board)
        n = len(board[0])

        should_crash = set()
        for row in range(m):
            for col in range(n):
                if board[row][col] == 0:
                    continue

                if row > 1 and board[row][col] == board[row-1][col] == board[row-2][col]:
                    should_crash.add((row, col))
                    should_crash.add((row-1, col))
                    should_crash.add((row-2, col))

                if col > 1 and board[row][col] == board[row][col-1] == board[row][col-2]:
                    should_crash.add((row, col))
                    should_crash.add((row, col-1))
                    should_crash.add((row, col-2))

        if should_crash:
            for row, col in should_crash:
                board[row][col] = 0
            return True

        return False

    def drop(self, board):
        m = len(board)
        n = len(board[0])

        for col in range(n):
            idx = len(board)-1
            for row in range(m-1, -1, -1):
                if board[row][col]>0:
                    board[idx][col] = board[row][col]
                    idx -= 1

            for row in range(idx+1):
                board[row][col] = 0

Javascript

var candyCrush = function(board) {
   let crush = false;
  // row
  for (let r = 0; r < board.length; r++) {
    for (let c = 0; c < board[r].length - 2; c++) {
      const target = Math.abs(board[r][c]);
      const allEqual = (target === Math.abs(board[r][c + 1])) && (target === Math.abs(board[r][c + 2]));
      if (board[r][c] !== 0 && allEqual) {
        board[r][c] = board[r][c + 1] = board[r][c + 2] = -target;
        crush = true;
      }
    }
  }

  // col
  for (let c = 0; c < board[0].length; c++) {
    for (let r = 0; r < board.length - 2; r++) {
      const target = Math.abs(board[r][c]);
      const allEqual = (target === Math.abs(board[r + 1][c])) && (target === Math.abs(board[r + 2][c]));

      if (board[r][c] !== 0 && allEqual) {
        board[r][c] = board[r + 1][c] = board[r + 2][c] = -target;
        crush = true;
      }
    }
  }

  for (let c = 0; c < board[0].length; c++) {
    let tmp = board.length - 1;
    for (let r = board.length - 1; r >= 0; r--) {
      if (board[r][c] > 0) {
        board[tmp--][c] = board[r][c]
      }
    }
    while (tmp >= 0) board[tmp--][c] = 0;
  }
  // console.log(board)

  if (crush) return candyCrush(board);
  else return board;
};