【練習04】 字典樹 1001 Hat’s Words

演算法思路：考察資料結構Trie。

在31ms的時候WA了幾次，後來發現是search函數的條件判斷出了問題，加了一個flag標記之後AC了。

很神奇的是最後也是31msAC的，難道上面的錯誤只有最後一個測試資料才能發現？還是judge是在所有列印完之後再檢查正確性的？

代碼如下：

//模板開始#include <string>   #include <vector>   #include <algorithm>   #include <iostream>   #include <sstream>   #include <fstream>   #include <map>   #include <set>   #include <cstdio>   #include <cmath>   #include <cstdlib>   #include <ctime>#include <iomanip>#include <string.h>#include <queue>#define SZ(x) (int(x.size()))using namespace std;int toInt(string s){istringstream sin(s); int t; sin>>t; return t;}template<class T> string toString(T x){ostringstream sout; sout<<x; return sout.str();}typedef long long int64;int64 toInt64(string s){istringstream sin(s); int64 t; sin>>t;return t;}template<class T> T gcd(T a, T b){ if(a<0) return gcd(-a, b);if(b<0) return gcd(a, -b);return (b == 0)? a : gcd(b, a % b);}//模板結束（通用部分）#define ifs cin#define maxnode 5000000#define maxword 50005#define wordlen 100#define sigma_size 26int count[maxnode];char words[maxword][wordlen];struct Trie{int ch[maxnode][sigma_size];int val[maxnode];int sz;Trie(){sz = 1;memset(ch[0], 0, sizeof(ch[0]));}int idx(char c){return c - 'a';}void insert(char* s, int v){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++;}u = ch[u][c];}val[u] = v;}int search(char* s, int n){int u = 0;int flag = 1;for(int i = 0; i < n; i++){int c = idx(s[i]);if(ch[u][c] == 0){flag = 0;break;}u = ch[u][c];}if(flag && val[u]){return 1;}else{return 0;}}};Trie t;//【練習04】 字典樹 1001 Hat’s Wordsint main(){//ifstream ifs("shuju.txt", ios::in);int wordsize = 0;while(ifs>>words[wordsize]){t.insert(words[wordsize], 1);wordsize++;}for(int i = 0; i < wordsize; i++){//cout<<sizeof(words[i])<<endl;int len = strlen(words[i]);//cout<<len<<endl;for(int j = 1; j < len; j++){//cout<<j<<endl;if(t.search(&words[i][0], j) && t.search(&words[i][j], len - j)){cout<<words[i]<<endl;break;}}}return 0;}