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【HDU】病毒侵袭持续中(AC自动机+map)

一开始一直WA,之后发现这道题不止一组输入,改成多组输入之后就过了。

利用map把每个字符串映射到它对应的结点上就行了。

119094672014-10-19 11:54:00Accepted3065234MS16912K2754 BG++KinderRiven

#include<queue>
#include<map>
#include<cstdio>
#include<string>
#include<vector>
#include<cstring>
#include<algorithm>
using namespace std;
const int maxn = 55555;
const int max_size = 130;
char ss[1111][55];
map<string,int>vis;
struct Trie{
    int next[maxn][max_size];
    int fail[maxn];
    int  val[maxn];
    int sz;
    int root;
    int num[maxn];
    int index(char e){
        return e - 31;
    }
    void init(){
        sz = 0;
        root = newnode();
    }
    int newnode(){
        val[sz] = 0; num[sz] = 0;
        memset(next[sz],-1,sizeof(next[sz]));
        sz ++;
        return sz - 1;
    }
    void insert(char *str){
        int L = strlen(str);
        int u = root;
        for(int i = 0; i < L; i++){
            int e = index(str[i]);
            if(next[u][e] == -1)
               next[u][e] = newnode();
           u = next[u][e];
        }
        val[u] = 1; //有单词
        vis[string(str)] = u;
    }
    void build(){ //建立失配边
        fail[root] = root;
        queue<int>q;
        for(int i = 0; i < max_size; 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 < max_size; i++){
                if(next[now][i] == -1)
                   next[now][i] = next[fail[now]][i];
                else{ //这个点是一个单词的结尾
                   fail[next[now][i]] = next[fail[now]][i];
                   q.push(next[now][i]);
                }
            }
        }
    }
    void count(char *str){
        int now = root;
        int L = strlen(str);
        for(int i = 0; i < L; i++){
            int e = index(str[i]);
            now = next[now][e];
            int temp = now;
            while(temp != root){
                if(val[temp]){ //如果这个结点是个单词末尾
                    num[temp] ++;
                    //printf("%d\n",temp);
                }
                temp = fail[temp];
            }
        }
    }
};
Trie ac;
char _str[2222222];
int main(){
    int n;
    while(scanf("%d",&n) != EOF){
        ac.init();
        vis.clear();
        getchar();
        for(int i = 0; i < n ; i ++){
             gets(ss[i]);
             ac.insert(ss[i]);
        }
        ac.build();
        gets(_str);
        ac.count(_str);
        for(int i = 0; i < n; i++){
            int t = vis[string(ss[i])];
            if(ac.num[t]){
                printf("%s: %d\n",ss[i],ac.num[t]);
            }
        }
    }
    return 0;
}

【HDU】病毒侵袭持续中(AC自动机+map)