AC自动机-HDU2896-模板题

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

另一道AC自动机的模板题,不过这题需要记录一下具体的匹配情况。

/*--------------------------------------------------------------------------------------*/
//        Helica's header 
//        Second Editions
//        2015.11.7
//
#include <algorithm>
#include <iostream>
#include <cstring>
#include <ctype.h>
#include <cstdlib>
#include <cstdio>
#include <vector>
#include <string>
#include <queue>
#include <stack>
#include <cmath>
#include <set>
#include <map>

//debug function for a N*M array 
#define debug_map(N,M,G) printf("
");for(int i=0;i<(N);i++)
{for(int j=0;j<(M);j++){
printf("%d",G[i][j]);}printf("
");}                
//debug function for int,float,double,etc.
#define debug_var(X) cout<<#X"="<<X<<endl;
/*--------------------------------------------------------------------------------------*/
using namespace std;

int N,M,T;
int tol;

struct Trie
{
    int next[100010][100],fail[100010],end[100010];
    int num[100010];
    int root,L;
    int cnt;
    int newnode()
    {
        for(int i=0;i<100;i++)
            next[L][i] = -1;
        end[L++] = 0;
        return L-1;
    }
    void init()
    {
        L = 0;
        root = newnode();
        memset(num,0,sizeof num);
        cnt = 1;
    }
    void insert(char *s)
    {
        int len = strlen(s);
        int now = root;
        for(int i=0;i<len;i++)
        {
            if(next[now][s[i]-'!'] == -1)
                next[now][s[i]-'!'] = newnode();
            now = next[now][s[i]-'!'];
        }
        end[now]++;
        num[now] = cnt++;
    }
    void build()
    {
        queue <int> Q;
        fail[root] = root;
        for(int i=0;i<100;i++)
        {
            if(next[root][i] == -1)
                next[root][i] = root;
            else
            {
                fail[next[root][i]] = root;
                Q.push(next[root][i]);
            }
        }
        while(! Q.empty())
        {
            int now = Q.front();
            Q.pop();
            for(int i=0;i<100;i++)
            {
                if(next[now][i] == -1)
                    next[now][i] = next[fail[now]][i];
                else
                {
                    fail[next[now][i]] = next[fail[now]][i];
                    Q.push(next[now][i]);
                }
            }
        }
    }
    void query(char *s,int no)
    {
        int len = strlen(s);
        int now = root;
        int ans = 0;
        set <int > web;

        for(int i=0;i<len;i++)
        {
            now = next[now][s[i]-'!'];
            int temp = now;
            while(temp != root)
            {
                ans += end[temp];
                if(end[temp]) web.insert(num[temp]);
                temp = fail[temp];
            }
        }
        if(!web.empty())
        {
            printf("web %d:",no);
            for(set <int>::iterator it=web.begin();it != web.end();it++)
                printf(" %d",*it);
            printf("
");
            tol++;
        }
    }
}ac;

char buf[10010];

int main()
{
    while(~scanf("%d",&N))
    {
        ac.init();
        tol = 0;
        for(int i=0;i<N;i++)
        {
            scanf("%s",buf);
            ac.insert(buf);
        }
        ac.build();
        scanf("%d",&M);
        for(int i=1;i<=M;i++)
        {
            scanf("%s",buf);
            ac.query(buf,i);
        }
        printf("total: %d
",tol);
    }
}
原文地址:https://www.cnblogs.com/helica/p/5037817.html