礼物的最大值

 1 public class Solution {
 2 
 3     public static void main(String[] args) {
 4         int[][] values = {
 5             {1,2,3},
 6             {4,5,6},
 7             {7,8,9}
 8         };
 9 
10         System.out.println(getMaxPathValue(values));
11     }
12 
13     private static int getMaxPathValue(int[][] values) {
14         if(values == null) {
15             return 0;
16         }
17 
18         int rows = values.length;
19         if(rows <= 0) {
20             return 0;
21         }
22 
23         int cols = values[0].length;
24         if(cols <= 0) {
25             return 0;
26         }
27 
28         int[][] maxValues = new int[rows][cols];
29         for(int i = 0; i < rows; i++) {
30             for(int j = 0; j < cols; j++) {
31 
32                 int left = 0;
33                 int up = 0;
34                 
35                 if(i > 0) {
36                     up = maxValues[i-1][j];
37                 }
38 
39                 if(j > 0) {
40                     left = maxValues[i][j-1];
41                 }
42 
43                 maxValues[i][j] = Math.max(up, left) + values[i][j];
44             }
45         }
46 
47         return maxValues[rows-1][cols-1];
48 
49     }
50 }