hdu 2896 病毒侵袭 夜

http://acm.hdu.edu.cn/showproblem.php?pid=2896

AC自动机

ASCII可见字符是从 33~126

代码:

#include<iostream>
#include<cmath>
#include<cstdio>
#include<string>
#include<cstring>
#include<vector>
#include<stack>
#include<queue>
#include<set>
#include<map>
#include<algorithm>

#define LL long long

using namespace std;

const int INF=0x3f3f3f3f;
const int N=10005;
const int M=505;
const int K=128;
struct nodeTrie
{
    nodeTrie()
    {
        v=0;
        fail=NULL;
        for(int i=0;i<K;++i)
        next[i]=NULL;
    }
    int v;
    nodeTrie *fail;
    nodeTrie *next[K];
}*root;
char s[N];
bool had[M];
void addWord(nodeTrie *p,char *s,int k)
{
    if(s[0]=='\0') return ;
    for(int i=0;s[i]!='\0';++i)
    {
        if(p->next[s[i]]==NULL)
        p->next[s[i]]=new nodeTrie;
        p=p->next[s[i]];
    }
    (p->v)=k;
}
void init(int n)
{
    root=new nodeTrie;
    for(int i=1;i<=n;++i)
    {
        gets(s);
        addWord(root,s,i);
    }
}
void bfs(nodeTrie *p)
{
    p->fail=root;
    queue<nodeTrie *>qt;
    qt.push(p);
    while(!qt.empty())
    {
        nodeTrie *y;
        nodeTrie *x=qt.front();qt.pop();
        for(int i=0;i<K;++i)
        if(x->next[i]!=NULL)
        {
            qt.push(x->next[i]);
            if(x==root)
            {x->next[i]->fail=root;continue;}
            y=x->fail;
            while(y!=root&&y->next[i]==NULL)
            y=y->fail;
            if(y->next[i]!=NULL)
            x->next[i]->fail=y->next[i];
            else
            x->next[i]->fail=root;
        }
    }
}
int match(nodeTrie *p,char *s)
{
    int wordCount=0;
    int l=0;
    while(s[l]!='\0')
    {
        while(p->next[s[l]]==NULL&&p!=root)
        p=p->fail;
        if(p->next[s[l]]!=NULL)
        p=p->next[s[l]];
        ++l;
        nodeTrie *fp=p;
        while(fp!=root)
        {
            if((fp->v)>0)
            {
                if(had[fp->v]==false)
                {++wordCount;had[fp->v]=true;}
            }
            fp=fp->fail;
        }
    }
    return wordCount;
}
void trieClear(nodeTrie *p)
{
    queue<nodeTrie *>qt;
    qt.push(p);
    while(!qt.empty())
    {
        nodeTrie *x=qt.front();qt.pop();
        for(int i=0;i<K;++i)
        if(x->next[i]!=NULL)
        qt.push(x->next[i]);
        delete x;
    }
}
int main()
{
    //freopen("data.in","r",stdin);
    int n;
    while(scanf("%d ",&n)!=EOF)
    {
        init(n);
        bfs(root);
        int m;
        scanf("%d ",&m);
        int total=0;
        for(int i=1;i<=m;++i)
        {
            gets(s);
            int k;
            memset(had,false,sizeof(had));
            k=match(root,s);
            if(k>0)
            {
                ++total;
                printf("web %d:",i);
                for(int j=1;j<=n;++j)
                if(had[j])
                printf(" %d",j);
                printf("\n");
            }
        }
        printf("total: %d\n",total);
        //trieClear(root);
    }
    return 0;
}

  

原文地址:https://www.cnblogs.com/liulangye/p/2975921.html