drone.java

public static class Wrapper{
    public static ArrayList<ArrayList<Integer>> paths; 
    public static ArrayList<Integer> mins;
    public static int max;
}
public static int maxScore2D(int[][] grid){
    Wrapper.paths = new ArrayList<ArrayList<Integer>>();
    Wrapper.mins = new ArrayList<Integer>();
    Wrapper.max = 0;
    ArrayList<Integer> path = new ArrayList<>();
    getMins(grid, 0, 1, grid[0][1], path);
    path.clear();
    getMins(grid, 1, 0, grid[1][0], path);
    return Wrapper.max;
}
public static void getMins(int[][] grid, int r, int c, int min, ArrayList<Integer> path){
    //if end found, save values.
    if(r == grid.length-1 && c == grid[0].length-1) {
        Wrapper.paths.add(path);
        Wrapper.mins.add(min);
        if(min > Wrapper.max) Wrapper.max = min;
        return;
    }
    //check if we have a new min for current brach path
    int newMin = min;
    if(grid[r][c] < min){
        newMin = grid[r][c];
    } 
    //Add current value to branch current path 
    path.add(grid[r][c]);
    //GO RIGHT
    if(c+1 < grid[0].length) {
        ArrayList<Integer> newPath = new ArrayList<Integer>(path);
        getMins(grid, r, c+1, newMin, newPath);   
    }
    //GO DOWN
    if(r+1 < grid.length) {
        ArrayList<Integer> newPath = new ArrayList<Integer>(path);
        getMins(grid, r+1, c, newMin, newPath);   
    }
}