FAFU 1557

构建字典序，模拟二叉树建26叉树

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <math.h>
#include <time.h>
#include <ctype.h>
#include <string>
#include <queue>
#include <set>
#include <map>
#include <stack>
#include <vector>
#include <algorithm>
#include <iostream>
#define PI acos( -1.0 )
using namespace std;
typedef long long ll;

const int NO = 1e5 + 5;
char ch[NO];
int n;
struct ND
{
    int win;
    ND *next[26];
};

int Solve( ND *tree )
{
    for( int i = 0; i < 26; ++i )
    {
        if( tree->next[i] == NULL ) continue;
        if( Solve( tree->next[i] ) )
        {
            tree->win = 0;
            return 0;
        }
    }
    tree->win = 1;
    return 1;
}

int main()
{
    int T;
    scanf( "%d", &T );
    while( T-- )
    {
        ND *tree;
        tree = new ND;
        for( int i = 0; i < 26; ++i )
            tree->next[i] = NULL;
        scanf( "%d", &n );
        for( int i = 0; i < n; ++i )
        {
            scanf( "%s", ch );
            ND *p = tree;
            int len = strlen( ch );
            for( int j = 0; j < len; ++j )
            {
                int cur = ch[j] - 'a';
                if( p->next[cur] == NULL )
                {
                    p->next[cur] = new ND;
                    p = p->next[cur];
                    p->win = 0;
                    for( int t = 0; t < 26; ++t )
                        p->next[t] = NULL;
                }
                else p = p->next[cur];
            }
        }
        if( !Solve( tree ) ) puts( "First." );
        else puts( "Second." );
    }
    return 0;
}