Ring HDU - 2296 AC自动机DP路径记录

#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("\n");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);
}
}