蓝桥杯 传纸条 dp

 1 #include <bits/stdc++.h>
 2 using namespace std;
 3 int mp[55][55];     //好心程度 | 权值
 4 int dp[55][55][55][55];
 5 int maxPath(int m, int n) {
 6     for (int x1 = 1; x1 <= m; x1++) {
 7         for (int y1 = 1; y1 <= n; y1++) {
 8             for (int x2 = 1; x2 <= m; x2++) {
 9                 for (int y2 = 1; y2 <= n; y2++) {
10                     if ((x1 < m || y1 < n) && x1 == x2 && y1 == y2) {
11                         continue;
12                     }
13                     dp[x1][y1][x2][y2] = max(max(dp[x1 - 1][y1][x2 - 1][y2], dp[x1 - 1][y1][x2][y2 - 1]), 
14                                               max(dp[x1][y1 - 1][x2 - 1][y2], dp[x1][y1 - 1][x2][y2 - 1]))
15                                              + mp[x1][y1] + mp[x2][y2];
16                 }
17             }
18         }
19     }
20     return dp[m][n][m][n]; 
21 }
22 int main() {
23     int m, n;
24     cin >> m >> n;
25     for (int i = 1;i <= m; i++) {
26         for (int j = 1;j <= n; j++) {
27             cin >> mp[i][j];
28         }
29     }
30     int ans = maxPath(m, n);
31     cout << ans << endl;
32     return 0;
33 }

 1 #include <bits/stdc++.h>
 2 using namespace std;
 3 int mp[55][55]; //好心程度 | 权值
 4 int dp[55 + 55][55][55];
 5 int maxPath(int m, int n) {
 6     for (int k = 1; k <= m + n - 3; k++) {
 7         for (int x1 = 0; x1 <= k; x1++) {
 8             for (int x2 = 0; x2 <= k; x2++) {
 9                 if (x1 == x2) { //x1 == x2 相当于(x1 == x2 && y1 = y2) 
10                     continue;
11                 }
12                 dp[k][x1][x2] = max(max(dp[k - 1][x1][x2], dp[k - 1][x1 - 1][x2 - 1]),
13                                     max(dp[k - 1][x1 - 1][x2], dp[k - 1][x1][x2 - 1]))
14                                     + map[x1][k - x1] + map[x2][k - x2];
15             }
16         }
17     }
18     return dp[m + n - 3][m - 1][m - 2];
19 }
20 int main() {
21     int m, n;
22     cin >> m >> n;    
23     for (int i = 0; i < m; i++) {
24         for (int j = 0; j < n; j++) {
25             cin >> mp[i][j];
26         }
27     }
28     int ans = maxPath(m, n);
29     cout << ans << endl;
30     return 0;
31 }