多阶段决策问题

 1 #include "iostream"
 2 #include "cstdio"
 3 #include "cstring"
 4 #include "string"
 5 #include "algorithm"
 6 using namespace std;
 7 const int maxn=100+10;
 8 const int INF=1<<30;
 9 int m,n;
10 int a[maxn][maxn];
11 int dp[maxn][maxn];
12 int Next[maxn][maxn];
13 int main()
14 {
15     //freopen("uva116.txt","r",stdin);
16     //freopen("uva116.out","w",stdout);
17     while(cin>>m>>n)
18     {
19         for(int i=1;i<=m;i++)
20             for(int j=1;j<=n;j++)
21                 cin>>a[i][j];
22         memset(Next,0,sizeof(Next));
23         int ans=INF,f=0;
24         for(int j=n;j>=1;j--){
25             for(int i=1;i<=m;i++){
26                 if(j==n){
27                     dp[i][j]=a[i][j];
28                 }else{
29                     int col[3]={i-1,i,i+1};
30                     if(i==1) col[0]=m;
31                     if(i==m) col[2]=1;
32                     sort(col,col+3);
33                     dp[i][j]=INF;
34                     for(int k=0;k<3;k++){
35                         int v=dp[col[k]][j+1]+a[i][j];
36                         if(v<dp[i][j]){
37                             dp[i][j]=v;
38                             Next[i][j]=col[k];
39                         }
40                     }
41                 }
42                 if(j==1&&ans>dp[i][j]){
43                     ans=dp[i][j];
44                     f=i;
45                 }
46             }
47         }
48         cout<<f;
49         for(int i=Next[f][1],j=2;j<=n;i=Next[i][j],j++)
50             cout<<" "<<i;
51         cout<<endl;
52         cout<<ans<<endl;
53     }
54     return 0;
55 }