zoukankan      html  css  js  c++  java
  • CodeForces

    Discription

    Arkady's code contains nn variables. Each variable has a unique name consisting of lowercase English letters only. One day Arkady decided to shorten his code.

    He wants to replace each variable name with its non-empty prefix so that these new names are still unique (however, a new name of some variable can coincide with some old name of another or same variable). Among such possibilities he wants to find the way with the smallest possible total length of the new names.

    A string aa is a prefix of a string bb if you can delete some (possibly none) characters from the end of bb and obtain aa.

    Please find this minimum possible total length of new names.

    Input

    The first line contains a single integer nn (1n1051≤n≤105) — the number of variables.

    The next nn lines contain variable names, one per line. Each name is non-empty and contains only lowercase English letters. The total length of these strings is not greater than 105105. The variable names are distinct.

    Output

    Print a single integer — the minimum possible total length of new variable names.

    Examples

    Input
    3
    codeforces
    codehorses
    code
    Output
    6
    Input
    5
    abba
    abb
    ab
    aa
    aacada
    Output
    11
    Input
    3
    telegram
    digital
    resistance
    Output
    3

    Note

    In the first example one of the best options is to shorten the names in the given order as "cod", "co", "c".

    In the second example we can shorten the last name to "aac" and the first name to "a" without changing the other names.

       很显然是可以在trie树上贪心的。

        每个点x开一个map,存单词结尾在x子树内的点的深度集合。

        如果点x没有被单词结尾覆盖,那么就把最深的放到这里。

        向上合并的时候启发式合并就好啦。。。。

        复杂度 O(N * log ^ 2(N))

    #include<bits/stdc++.h>
    #include <typeinfo> 
    #define ll long long
    using namespace std;
    const int maxn=100005;
    
    map<int,int> mmp[maxn];
    map<int,int> :: iterator it;
    int ch[maxn][26],cnt,n,N,ans,dep[maxn],word[maxn];
    char S[maxn];
    
    inline void ins(){
    	int now=0,c,depth=0;
    	for(int i=0;i<N;i++){
    		c=S[i]-'a';
    		if(!ch[now][c]) ch[now][c]=++cnt;
    		now=ch[now][c],dep[now]=++depth;
    	}
    	
    	word[now]++;
    }
    
    void dfs(int x){
    	for(int i=0,to;i<26;i++) if(ch[x][i]){
    		to=ch[x][i],dfs(to);
    		
    		if(mmp[to].size()>mmp[x].size()) swap(mmp[to],mmp[x]);
    		
    		for(it=mmp[to].begin();it!=mmp[to].end();++it) mmp[x][it->first]+=it->second;
    		    
    		mmp[to].clear();
    	}
    	
    	if(word[x]) mmp[x][dep[x]]+=word[x];
    	else if(x){
    		it=--mmp[x].lower_bound(1e9);
    
    		ans-=(it->first)-dep[x];
    		
    		if(!(--(it->second))) mmp[x].erase(it);
    		
    		mmp[x][dep[x]]++;
    	}
    }
    
    
    int main(){
    	scanf("%d",&n);
    	for(int i=1;i<=n;i++){
    		fill(S,S+N,0);
    		scanf("%s",S),N=strlen(S),ans+=N;
    		ins();
    	}
    	
    	dfs(0);
    	
    	printf("%d
    ",ans);
    	return 0;
    }
    

      

  • 相关阅读:
    TCP 连接断连问题剖析
    libtool: link: you must specify an output file
    socket编程bind浮动ip
    epoll或者kqueue的原理是什么?
    推荐 30 款最好的免费项目管理软件
    QNX开发最完整图文教程(官方文档,非官方翻译)
    Android 4.X系列の界面设计中退出Android程序的代码
    APScheduler 定时任务系统
    给定一个整数数组 nums 和一个整数目标值 target,请你在该数组中找出 和为目标值 target  的那 两个 整数,并返回它们的数组下标。
    APSchenuler嵌入Django
  • 原文地址:https://www.cnblogs.com/JYYHH/p/9167829.html
Copyright © 2011-2022 走看看