zoukankan      html  css  js  c++  java
  • HDU 2222 ----AC自动机

    Problem Description
    In the modern time, Search engine came into the life of everybody like Google, Baidu, etc.
    Wiskey also wants to bring this feature to his image retrieval system.
    Every image have a long description, when users type some keywords to find the image, the system will match the keywords with description of image and show the image which the most keywords be matched.
    To simplify the problem, giving you a description of image, and some keywords, you should tell me how many keywords will be match.
     
    Input
    First line will contain one integer means how many cases will follow by.
    Each case will contain two integers N means the number of keywords and N keywords follow. (N <= 10000)
    Each keyword will only contains characters 'a'-'z', and the length will be not longer than 50.
    The last line is the description, and the length will be not longer than 1000000.
     
    Output
    Print how many keywords are contained in the description.
     
    Sample Input
    1 5 she he say shr her yasherhs
     
    Sample Output
    3
     
     
     
    AC自动机,李大神刚刚讲过的内容来一发练习,模板大法好!
    #include<iostream>
    #include<stdio.h>
    #include<algorithm>
    #include<string.h>
    #include<queue>
    using namespace std;
    
    struct Trie
    {
        int next[500010][26],fail[500010],end[500010];
        int root,L;
        int newnode()
        {
            for(int i=0;i<26;i++)
            {
                next[L][i]=-1;
            }
            end[L++]=0;
            return L-1;
        }
        void init()
        {
            L=0;
            root=newnode();
        }
        void insert(char buf[])
        {
            int len=strlen(buf);
            int now=root;
            for(int i=0;i<len;i++)
            {
                if(next[now][buf[i]-'a']==-1)
                    next[now][buf[i]-'a']=newnode();
                now=next[now][buf[i]-'a'];
            }
            end[now]++;
        }
        void build()
        {
            queue<int>q;
            fail[root]=root;
            for(int i=0;i<26;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<26;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]);
                    }
                }
            }
        }    
        int query(char buf[])
        {
            int len=strlen(buf),now=root,res=0;
            for(int i=0;i<len;i++)
            {
                now=next[now][buf[i]-'a'];
                int temp=now;
                while(temp!=root)
                {
                    res+=end[temp];
                    end[temp]=0;
                    temp=fail[temp];
                }
            }
            return res;
        }
    };
    
    char buf[1000010];
    Trie ac;
    int main()
    {
        //freopen("in.txt","r",stdin);
        int T,n;
        scanf("%d",&T);
        while(T--)
        {
            scanf("%d",&n);
            ac.init();
            for(int i=0;i<n;i++)
            {
                scanf("%s",buf);
                ac.insert(buf);
            }
            ac.build();
            scanf("%s",buf);
            printf("%d
    ",ac.query(buf));
        }
        return 0;
    }
    View Code
  • 相关阅读:
    Web APP开发技巧总结
    2015年 移动开发都有哪些热点?
    手机APP UI设计尺寸基础知识
    最新Android & iOS设计尺寸规范
    给iOS开发者的Android开发建议
    Android 应用开发推荐书单
    Android 你应该知道的学习资源 进阶之路贵在坚持
    一篇文章让你读懂iOS和Android的历史起源
    Android平台上最好的几款免费的代码编辑器
    Google 发布的15个 Android 性能优化典范
  • 原文地址:https://www.cnblogs.com/dzzy/p/4907421.html
Copyright © 2011-2022 走看看