POJ3630

Tire树裸题，一开始写动态的字典树，然后TLE，每次new一个新节点耗费时间较多。后来改成数组模拟的。

//#include <bits/stdc++.h>
#include <cstdio>
#include <cstring>
#include <algorithm>

using namespace std ;
const int maxN =  ; 

struct stringStruct {
    char str[  ] ;
    int len ;
}ss[ maxN ] ; 

struct tireNode {
    int cnt ;
    bool last ;
    struct tireNode *next[  ] ;
    tireNode ( ) {
        cnt =  ;
        last = false;
        memset ( next ,  , sizeof ( next ) ) ;
    }
};

bool cmp ( stringStruct a , stringStruct b ) {
    return a.len < b.len ;
}

bool insert ( tireNode *root , char str[ ] ) {
    int len = strlen ( str ) ;
    tireNode *cur = root ;

    for ( int i= ; i<len ; ++i ) {
        char ch = str[ i ] - '' ;
        if ( cur -> next[ ch ] == NULL ) {
            tireNode* newNode = new tireNode ;
            cur -> next[ ch ] = newNode ;
        }
        if ( cur -> last ) return true ;
        cur = cur -> next[ ch ] ;
        cur->cnt++ ;
    }
    cur -> last = true ;
    return false ;
}

int main ( ) {
    int T ;
    for ( scanf( "%d" , &T ) ; T ; --T ) {
        tireNode* root = new tireNode ;
        int N ;
        scanf ( "%d\n" , &N ) ;
        for ( int i= ; i<=N ; ++i ) {
            char ch = getchar ( ) ;
            int lenn =  ;
            while ( ch != '\n' ) {
                ss[ i ].str[ lenn++ ] = ch ;
                ch = getchar ( ) ;
            }
            ss[ i ].len = lenn ;
        }
        sort ( ss +  , ss + N +  , cmp ) ;
        bool flag = true ;
        for ( int i= ; i<=N ; ++i ) {
            if ( insert ( root , ss[ i ].str ) ) {
                flag = false ;
                break ;
            }
        }
        if ( flag ) printf ( "YES\n" ) ;
        else printf ( "NO\n" ) ;
    }
    return  ;
}

TLE动态字典树

#include <cstdio>
#include <algorithm>
#include <cstring>

using namespace std ;
const int maxN =  ;
typedef long long LL ; 

struct stringStruct {
    char str[  ] ;
    int len ;
}ss[ maxN ] ; 

int trie[ maxN ][  ] ;
bool end[ maxN ] ;
bool cmp ( stringStruct a , stringStruct b ) {
    return a.len < b.len ;
}

int _cnt ;

bool insert ( char str[ ] ) {
    int cur =  , len = strlen ( str +  ) ;
    for ( int i= ; i<=len ; ++i ) {
        int ch = str[ i ] - '' ;
        if ( !trie[ cur ][ ch ] )
            trie[ cur ][ ch ] = ++_cnt ;
        if ( end[ cur ] ) return true ;
        cur = trie[ cur ][ ch ] ;
    }
    end[ cur ] = true ;
    return false ;
}

int main ( ) {
    int T , N ;
    for ( scanf ( "%d" , &T ) ; T ; --T ) {
        memset ( trie ,  , sizeof ( trie ) ) ;
        memset ( end , false , sizeof ( end ) ) ;
        _cnt =  ;
        scanf ( "%d" , &N ) ;
        for ( int i= ; i<=N ; ++i ) {
            scanf ( "%s" , ss[ i ].str +  ) ;
            ss[ i ].len = strlen ( ss[ i ].str +  ) ;
        }
        sort ( ss +  , ss + N +  , cmp ) ;
        bool flag = true ;
        for ( int i= ; i<=N ; ++i ) {
            if ( insert ( ss[ i ].str ) ) {
                flag = false ;
                break ;
            }
        }
        if ( flag )printf ( "YES\n" ) ;
        else printf ( "NO\n" ) ;
    }
    return  ;
}

AC数组模拟