Bomb Enemy.java

public class Solution {
    /*
     * @param grid: Given a 2D grid, each cell is either 'W', 'E' or '0'
     * @return: an integer, the maximum enemies you can kill using one bomb
     */
    public int maxKilledEnemies(char[][] grid) {
        // write your code here
        if (grid == null || grid.length == 0) {
            return 0;
        }
        int m = grid.length, n = grid[0].length, res = 0, rowCnt = 0;
        int[] colCnt = new int[n];
        for (int i = 0; i < m; ++i) {
            for (int j = 0; j < n; ++j) {
                if (j == 0 || grid[i][j - 1] == 'W') {
                    rowCnt = 0;
                    for (int k = j; k < n && grid[i][k] != 'W'; ++k) {
                        rowCnt += grid[i][k] == 'E' ? 1 : 0;
                    }
                }
                if (i == 0 || grid[i - 1][j] == 'W') {
                    colCnt[j] = 0;
                    for (int k = i; k < m && grid[k][j] != 'W'; ++k) {
                        colCnt[j] += grid[k][j] == 'E' ? 1 : 0;
                    }
                }
                if (grid[i][j] == '0') {
                    res = Math.max(res, rowCnt + colCnt[j]);
                }
            }
        }
        return res;
    }
}