凍龜之前

先看地龜

 1 //
 2 // Created by snnnow on 2020/7/23
 3 //
 4 //遞迴演算法，除了慢其實還好
 5 #include<iostream>
 6 #include<stdio.h>
 7 #include<stdlib.h>
 8 #include<time.h>
 9 #include <queue>
10 using namespace std;
11 #define Max 101
12 int m[Max][Max];
13 int n;
14 int dfs(int a,int b){
 
15     if(a==n)
16         return m[a][b];
17     return max(dfs(a+1,b),dfs(a+1,b+1))+m[a][b];
18 }
19 int main(){
20 
21     scanf("%d",&n);
22     for (int i = 1; i <= n; ++i) {
23         for (int j = 1; j <= i ; ++j) {
24             scanf("%d",&m[i][j]);
25 
26         }
27 
28     }
 
29     printf("%d",dfs(1,1));
30 }

加個記憶化搜素

 1 //
 2 // Created by snnnow on 2020/7/23
 3 //
 4 //遞迴演算法，除了慢其實還好
 5 #include<iostream>
 6 #include<stdio.h>
 7 #include<stdlib.h>
 8 #include<time.h>
 9 #include <queue>
10 #include <time.h>
11 using namespace std;
12 #define Max 101
13
 
 int m[Max][Max];
14 int rem[Max][Max];
15 int n;
16 int dfs(int a,int b){
17     if(rem[a][b]!=-1)
18         return rem[a][b];
19     if(a==n)
20         rem[a][b]= m[a][b];
21     else
22         rem[a][b]=max(dfs(a+1,b),dfs(a+1,b+1))+m[a][b];
23 
24     return rem[a][b];
25 }
26 int main(){
27 
28     scanf("%d",&n);
29     for (int i = 1; i <= n; ++i) {
30         for (int j = 1; j <= i ; ++j) {
31             scanf("%d",&m[i][j]);
32             rem[i][j]=-1;
33 
34         }
35 
36     }
37     printf("%d",dfs(1,1));
38     cout<<endl;
39     printf("Time used = %.2f\n", (double)clock() / CLOCKS_PER_SEC);
40 
41 }