AC自动机

HDU 3065

输入一个整数N，然后输入N个字符串。最后输入一行字符串。输出这N个字符串在最后一行字符串中出现的次数，如果没有在最后一行出现，则不输出。

 

Sample Input

3AABBCCooxxCC%dAAAoen....END

 

 

Sample Output

AA: 2CC: 1

 

 

#include <stdio.h>
#include <string.h>
#include <queue>
using namespace std;

#define N 2000100
#define maxnode 50010
#define sigma_size 26
struct node{
    char name[55];
    int num;
}S[1101];
struct Trie{
    int ch[maxnode][sigma_size];
    int val[maxnode];
    int f[maxnode];
    int sz;
    void init(){
        sz=1;
        memset(ch,0,sizeof(ch));
        memset(val,0,sizeof(val));
        memset(f,0,sizeof(f));
        val[0] = 0;
    }
    int idx(char c){
        return c-'A';
    }

    void Creat(char *s, int num){
        int u = 0, len = strlen(s);
        for(int i = 0; i < len; i++){
            int c = idx(s[i]);
            if(!ch[u][c]) ch[u][c] = sz++;
            u = ch[u][c];
        }
        val[u] = num ; //u若是单词结尾则为 +1
    }

    int find(char *T){
        int len = strlen(T);
        int j = 0;
        for(int i = 0; i < len; i++){
            if(T[i]<'A' || T[i]>'Z'){ j = 0; continue;}
            int c = idx(T[i]);
            j = ch[j][c];
            int temp = j;
            while(temp && val[temp]){
                S[ val[temp] ].num ++;
                temp = f[ temp ];
            }
        }

        return 0;
    }

    void getFail(){
        queue<int> q;
        //初始化队列
        for(int c = 0; c < sigma_size; c++)
            if(ch[0][c])q.push(ch[0][c]);

        while(!q.empty()){
            int r = q.front(); q.pop();
            for(int c = 0; c < sigma_size; c++){
                int u = ch[r][c];
                if(!u){ ch[r][c] = ch[f[r]][c]; continue; }
                q.push(u);
                int v = f[r];
                while(v && !ch[v][c]) v = f[v]; //沿失配边追溯到可以匹配的(非原点)位置
                f[u] = ch[v][c];
            }
        }
    }
};
Trie ac;
char S1[N];

int main(){
    int n;
    while(~scanf("%d",&n)){
        ac.init();
        for(int i = 1; i <= n; i++){
            scanf("%s",S[i].name);
            S[i].num = 0;
            ac.Creat(S[i].name, i);
        }
        ac.getFail();

        scanf("%s",S1);
        ac.find(S1);

        for(int i = 1; i <= n; i++)
            if(S[i].num)
                printf("%s: %d\n",S[i].name, S[i].num);

    }
    return 0;
}