Solution.java

public class Solution {
    public int minPathSum(int[][] grid) {
        int xl=grid.length;
        int yl=grid[0].length;
        Map<String, Integer> map=new HashMap<String, Integer>();
        return f(grid,0,0,xl,yl,map);
    }
    public int f(int[][] grid,int x,int y,int xl,int yl,Map<String, Integer> map){
        String coordinate=x+","+y;
        if (map.get(coordinate)==null) {
            if (x>=xl||y>=yl) {
                return -1;
            }else {
                int xv=f(grid,x+1,y,xl,yl,map);
                int yv=f(grid,x,y+1,xl,yl,map);
               int v=0;
               if (xv<0) {
                    v=yv;
                }else if (yv<0) {
                    v=xv;
                }else if (xv>yv){
                    v=yv;
                }else {
                    v=xv;
                }
                int value=grid[x][y]+(v<0?0:v);
                map.put(coordinate, value);
                return value;
            }
        }
        return map.get(coordinate);
    }
}