uva116 Unidirectional TSP

#include<bits/stdc++.h>
#define REP(i,a,b) for(int i=a;i<=b;i++)
#define MS(a) memset(a,0,sizeof(a))
#define MS1(a) memset(a,-1,sizeof(dp))

using namespace std;

typedef long long ll;
const int maxn=1100;
const int INF=1<<29;

int n,m;
int a[maxn][maxn];
int dp[maxn][maxn];
int nx[maxn][maxn];

int dfs(int i,int j)
{
    int &res=dp[i][j];
    if(~res) return res;
    if(i==n) return res=a[i][j];
    int nj[3]={j,(j-2+m)%m+1,j%m+1};
    sort(nj,nj+3);
    res=INF;
    REP(k,0,2){
        int t=dfs(i+1,nj[k])+a[i][j];
        if(t<res){
            res=t;
            nx[i][j]=nj[k];
        }
    }
    return res;
}

int main()
{
    freopen("in.txt","r",stdin);
    while(cin>>m>>n){
        if(m==0) break;
        REP(i,1,m) REP(j,1,n) scanf("%d",&a[j][i]);
        /*
        REP(i,1,m){
            REP(j,1,n) cout<<a[j][i]<<" ";
            cout<<endl;
        }
        */
        MS1(dp);MS1(nx);
        int ans=INF;
        int x=1;
        REP(i,1,m){
            int t=dfs(1,i);
            if(t<ans) ans=t,x=i;
        }
        //cout<<"ans="<<ans<<endl;
        printf("%d",x);
        int cur=1;
        for(int i=nx[cur][x];i!=-1;cur++,i=nx[cur][i]) printf(" %d",i);
        printf("
%d
",ans);
    }
    return 0;
}
/**
还是用dfs去弄字典序最小比较方便,终于AC了
*/