uva 10391复合词compound words（Trie+set）

标签：前缀树   string   uva   set   

给定一个词典，要求求出其中所有的复合词，即恰好有两个单词连接而成的词

trie存储以该单词为前缀的单词数量，然后对于每个单词，看在字典中的以该单词为前缀的单词“减去”原单词剩下的单词是否在字典中，如果是储存这个答案到ans的set中

#include<cstdio>  
#include<cstring>  
#include<cmath>  
#include<cstdlib>  
#include<iostream>  
#include<algorithm>  
#include<vector>  
#include<map>  
#include<queue>  
#include<stack> 
#include<string>
#include<map> 
#include<set>
#define eps 1e-6 
#define LL long long  
using namespace std;  

const int maxn = 120000 + 100;
const int INF = 0x3f3f3f3f;

struct Trie {
	int ch[maxn][30];
	int val[maxn];
	int sz;
	Trie() {
		sz = 1; memset(ch[0], 0, sizeof(ch[0]));
	}
	int idx(char c) { return c - 'a';}
	
	void insert(char *s) {
		int u = 0, n = strlen(s);
		for(int i = 0; i < n; i++) {
			int c = idx(s[i]);
			if(!ch[u][c]) {
				memset(ch[sz], 0, sizeof(ch[sz]));
				val[sz] = 0;
				ch[u][c] = sz++;
			}
			else val[ch[u][c]]++;
			u = ch[u][c];
		}
	}
	
	int find(char *s) {
		int u = 0, n = strlen(s);
		for(int i = 0; i < n; i++) {
			int c = idx(s[i]);
			if(!ch[u][c]) return 0;
			u = ch[u][c];
		}
		return val[u];
	}
} trie;

vector<string> dic;
set<string> word;
set<string> ans;
void init() {
	string tmp;
	while(cin >> tmp) {
		dic.push_back(tmp);
		word.insert(tmp);
		trie.insert((char *)tmp.c_str());
	}
}

void solve() {
	int sz = dic.size();
	for(int i = 0; i < sz; i++) {
		//cout << (char *)dic[i].c_str() << endl;
		int cnt = trie.find((char *)dic[i].c_str());// cout << cnt << endl;
		int wsz = dic[i].size();
		for(int j = 1; j <= cnt; j++) {
			if(word.count(dic[i+j].substr(wsz, dic[i+j].size()-wsz)))
				ans.insert(dic[i+j]);
		}
	}
	for(set<string>::iterator it = ans.begin(); it != ans.end(); it++) cout << *it << endl;
}

int main() {
//	freopen("input.txt", "r", stdin);
	init();
	solve();
	return 0;
}

uva 10391复合词compound words（Trie+set）

标签：前缀树   string   uva   set   

原文地址：http://blog.csdn.net/u014664226/article/details/46502435