zoukankan      html  css  js  c++  java
  • hdu 2222 Keywords Search AC自动机模板题

    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

    这道题完全套用模板,但是注意的是有可能有多个相同的模式串,算总和的时候都要算上。

    #include<queue>
    #include<cstring>
    #include<cstdio>
    using namespace std;
    int ch[10002*52][26],End[10002*52],cur,fail[10002*52],last[10002*52],ans[10002];
    char str[1000005],str0[10002][52];
    int sum[10002*52];
    void get_fail()
    {
        int now,tmpFail,Next;
        queue<int> q;
        for(int j=0; j<26; j++)
        {
            if(ch[0][j])
            {
                q.push(ch[0][j]);
                fail[ch[0][j]] = 0;
                last[ch[0][j]] = 0;
            }
        }
        while(!q.empty())
        {
            now = q.front();
            q.pop();
            for(int j=0; j<26; j++)
            {
                if(!ch[now][j]) continue;
                Next = ch[now][j];
                q.push(Next);
                tmpFail = fail[now];
                while(tmpFail&&!ch[tmpFail][j]) tmpFail = fail[tmpFail];
                fail[Next] = ch[tmpFail][j];
                last[Next] = End[fail[Next]] ? fail[Next]:last[fail[Next]];
            }
        }
    }
    void Find ()
    {
        int now = 0;
        int len = strlen(str);
        for(int i=0; i<len; i++)
        {
            if(str[i]<'a'||str[i]>'z')
            {
                now=0;
                continue;
            }
            str[i]-='a';
            while(now&&!ch[now][str[i]]) now = fail[now];
            now = ch[now][str[i]];
            if(End[now]) ans[End[now]]++;
            int tmp = now;
            while(last[tmp])
            {
                ans[End[last[tmp]]]++;
                tmp = last[tmp];
            }
        }
    }
    int main()
    {
        int n,now,T;
        scanf("%d",&T);
        while(T--)
        {
            scanf("%d",&n);
            memset(ch,0,sizeof(ch));
            memset(End,0,sizeof(End));
            memset(ans,0,sizeof(ans));
            memset(last,0,sizeof(last));
            memset(sum,0,sizeof(sum));
            cur = 1;
            int len;
            for(int i=1; i<=n; i++)
            {
                scanf("%s",str0[i]);
                len = strlen(str0[i]);
                now = 0;
                for(int j=0; j<len; j++)
                {
                    str0[i][j]-='a';
                    if(ch[now][str0[i][j]]==0) ch[now][str0[i][j]] = cur++;
                    now = ch[now][str0[i][j]];
                    str0[i][j]+='a';
                }
                if(End[now]) sum[End[now]]++;
                else {
                    sum[i] = 1;
                    End[now] = i;
                }
            }
            get_fail();
            scanf("%s",str);
            Find();
            int res=0;
            for(int i=1; i<=n; i++)
            {
                if(ans[i]) res+=sum[i];
                //sum+=ans[i];
            }
            printf("%d
    ",res);
        }
    }
  • 相关阅读:
    中层人才轮岗,张勇宣布阿里新一轮组织架构调整
    公司倒闭 1 年了,而我当年的项目上了 GitHub 热榜
    为什么别人的行业都那么让人羡慕
    ClickHouse 高级(五)数据一致性(重点)
    ClickHouse 高级(四)优化(4)查询优化
    ClickHouse 高级(二)优化(2)建表优化
    ClickHouse 高级(一)优化(1)Explain 查看执行计划
    ClickHouse基础(八)使用基础(5)ClickHouse 的安装(win10)
    【简单的原创】div简单轮换显示
    BZOJ 5494: [2019省队联测]春节十二响 (左偏树 可并堆)
  • 原文地址:https://www.cnblogs.com/lastone/p/5341598.html
Copyright © 2011-2022 走看看