Leetcode64. Minimum path sum

Title transmission address : https://leetcode.cn/problems/minimum-path-sum/

Operational efficiency ：

The code is as follows :

public int minPathSum(int[][] grid) {
    
        // The coordinates of the lower right corner 
        int m = grid.length - 1;
        int n = grid[0].length - 1;
        HashMap<String,Integer> map = new HashMap<>();
        int path = minPath(m, n, grid,map);
        return path;
    }

    public int minPath(int m, int n, int[][] grid, HashMap<String,Integer> map) {
    
        String key = m + ":" + n;
        if(map.containsKey(key)){
    
           return map.get(key);
        }
        // Dealing with border situations 
        if (m == 0) {
    
            int path = grid[0][n];
            while (n > 0) {
    
                path += grid[0][n - 1];
                n--;
            }
            return path;
        }
        if (n == 0) {
    
            int path = grid[m][0];
            while (m > 0) {
    
                path += grid[m-1][0];
                m--;
            }
            return path;
        }
        // Go to the (m,n) The location is 2 Seed walking method , The first is from (m-1,n) To (m,n)  The second is from the (m,n-1) To (m,n)
        int i = minPath(m - 1, n, grid,map);
        int j = minPath(m, n - 1, grid,map);
        int res = Math.min(i, j) + grid[m][n];
        map.put(key,res);
        return res;
    }