361. Bomb Enemy

class Solution {
    public int maxKilledEnemies(char[][] grid) {
        if(grid == null || grid.length < 1 || grid[0].length < 1) return 0;
        int m = grid.length, n = grid[0].length, re = 0;
        int[][] L = new int[m][n], R = new int[m][n], U = new int[m][n], D = new int[m][n];
        for(int i = 0; i < m; i++)
        {
            for(int j = 1; j < n; j++)
            {
                L[i][j] = (grid[i][j - 1] == 'E' ? 1 : 0) + L[i][j - 1];
                if(grid[i][j] == 'W') L[i][j] = 0;
            }
            for(int j = n - 2; j >= 0; j--)
            {
                R[i][j] = (grid[i][j + 1] == 'E' ? 1 : 0) + R[i][j + 1];
                if(grid[i][j] == 'W') R[i][j] = 0;
            }
        }
        for(int j = 0; j < n; j++)
        {
            for(int i = 1; i < m; i++)
            {
                U[i][j] = (grid[i - 1][j] == 'E' ? 1 : 0) + U[i - 1][j];
                if(grid[i][j] == 'W') U[i][j] = 0;
            }
            for(int i = m - 2; i >= 0; i--)
            {
                D[i][j] = (grid[i + 1][j] == 'E' ? 1 : 0) + D[i + 1][j];
                if(grid[i][j] == 'W') D[i][j] = 0;
            }
        }
        for(int i = 0; i < m; i++)
        {
            for(int j = 0; j < n; j++)
            {
                if(grid[i][j] == '0') re = Math.max(re, L[i][j] + D[i][j] + U[i][j] + R[i][j]);
            }
        }
        return re;
    }
}