原题

package snapchat;

/**
 * Created by kangyue on 1/5/17.
 */
public class GoMyth {

    public boolean go(int[][] matrix){

        int row = matrix.length;

        if(row == 0)return false;
        int col = matrix[0].length;

        for(int i = 0; i < row; i++){
            for(int j = 0; j < col; j++){
                if(matrix[i][j] == 1)return dfs(matrix,i,j,new boolean[row][col]);
            }
        }

        return false;

    }

    public boolean dfs(int[][] matrix, int i, int j, boolean[][] visit){
        if(matrix[i][j] == 9)return true;

        visit[i][j] = true;

        int row = matrix.length;
        int col = matrix[0].length;

        int[] dx = new int[]{1,-1,0,0};
        int[] dy = new int[]{0,0,1,-1};

        for(int k = 0; k < 4; k++){
            int nx = i + dx[k];
            int ny = j + dy[k];

            if(nx >= 0 && nx < row && ny >= 0 && ny < col && matrix[nx][ny] != 5 && !visit[nx][ny]){
                if(dfs(matrix,nx,ny,visit))return true;
            }
        }

        return false;
    }

    public static void main(String[] args){
        GoMyth gm = new GoMyth();
        int[][] tester = new int[][]{{1,0,0,0,0},{0,0,0,5,0},{0,0,0,5,9}};
        System.out.println(gm.go(tester));
    }
}