Ring HDU

构造n长串,若含有模板串x可获得a[x]的价值,同价值取字典序最小,输出路径

dp[i][j]表示长度i转移态j的最大价值,对应一个path[i][j]记录路径

#include<bits/stdc++.h>
#include<stdio.h>
#include<algorithm>
#include<queue>
#include<string.h>
#include<iostream>
#include<math.h>
#include<set>
#include<map>
#include<vector>
#include<iomanip>
using namespace std;
#define ll long long
#define ull unsigned long long
#define pb push_back
#define FOR(a) for(int i=1;i<=a;i++)
const int inf=0x3f3f3f3f;
const int maxn=1e6+7; 
const long long mod=1e9+7;
const int sigma=26;

ll ans;

int a[110];
int dp[55][1111];	//串长i匹配到j位置最大价值
string path[55][1111];	//路径

struct automata{  
    int ch[maxn][sigma];  
    int val[maxn];  
    int f[maxn];  
    int sz;  
  
    int newnode(){  
        memset(ch[sz],0,sizeof(ch[sz]));  
        f[sz]=val[sz]=0;  
        return sz++;  
    }  
  
    void init(){  
        memset(val,0,sizeof(val));  
        sz=0;  
        newnode();  
    }  
  
    void insert(char *s,int v){   
        int u=0;  
        int len=strlen(s);  
        for(int i=0;i<len;i++){  
            int id=s[i]-'a';  
            if(!ch[u][id])ch[u][id]=newnode();  
            u=ch[u][id]; 
        }  
    	val[u]=v;
	}  
	void solve(int n){
		memset(dp,-1,sizeof dp);
		dp[0][0]=0;path[0][0]="";
		for(int i=0;i<n;i++){
			for(int j=0;j<sz;j++){
				if(dp[i][j]!=-1){	//可达,更新后继
					for(int k=0;k<26;k++){
						int u=ch[j][k];
						if(dp[i][j]+a[val[u]] > dp[i+1][u]){
							dp[i+1][u]=dp[i][j]+a[val[u]];
							path[i+1][u]=path[i][j]+(char)(k+'a');
							continue;
						}
						if(dp[i][j]+a[val[u]]==dp[i+1][u]){
							string str=path[i][j];
							str.pb(k+'a');
							if(str<path[i+1][u])path[i+1][u]=str;
						}
					}
				}
			}
		}
		int ans=0,row;
		string str; 
		for(int i=0;i<=n;i++)
			for(int j=0;j<sz;j++)
				if(ans<dp[i][j]){
					ans=dp[i][j];row=i;
				}
			
		
		if(ans==0){printf("
");return;}
		str="";
		for(int j=0;j<sz;j++){
			if(dp[row][j] == ans && (str>path[row][j]||str==""))
				str=path[row][j];
		}
		cout<<str<<endl;
	}
  
    void build(){  
        queue<int>q;  
        q.push(0);    
        while(!q.empty()){  
            int u=q.front();q.pop();  
            if(val[f[u]]){ 
            	//val[u]=(val[u]+val[f[u]];  
            	a[val[u]]+=a[val[f[u]]];
			}  	
            for(int i=0;i<sigma;i++){  
                int v=ch[u][i];  
                if(!v)ch[u][i]=ch[f[u]][i];  
                else q.push(v);  
                if(u&&v)f[v]=ch[f[u]][i];  
            }  
        }  
    }  
     
}ac; 

char buf[60];
int n,m;
int main(){
	int T;scanf("%d",&T);
	while(T--){
		scanf("%d%d",&n,&m);
		ac.init();
		for(int i=1;i<=m;i++){
			scanf("%s",buf);
			ac.insert(buf,i);
		}
		for(int i=1;i<=m;i++)scanf("%d",&a[i]);
		ac.build();ac.solve(n);
	}
}


原文地址:https://www.cnblogs.com/Drenight/p/8611275.html