面试题47. 礼物的最大价值

 1 class Solution {
 2 public:
 3     int maxValue(vector<vector<int>>& grid) 
 4     {
 5         int m = grid.size();
 6         int n = grid[0].size();
 7 
 8         for (int i = 0; i < m; i++)
 9         {
10             for (int j = 0; j < n; j++)
11             {
12                 if (i == 0 && j == 0)
13                 {
14                     continue;
15                 }
16                 if (i == 0)
17                 {
18                     grid[i][j] += grid[i][j - 1] ;
19                 }
20                 else if (j == 0)
21                 {
22                     grid[i][j] += grid[i - 1][j];
23                 }
24                 else
25                 {
26                     grid[i][j] += std::max(grid[i][j - 1], grid[i - 1][j]);
27                 }
28             }
29         }
30 
31         return grid[m - 1][n - 1];
32     }
33 };