poj 2001 Shortest Prefixes

还是字典树的基础题，纯粹为了熟练代码，加深理解

#include <set>#include <map>#include <ctime>#include <queue>#include <cmath>#include <stack>#include <limits>#include <vector>#include <bitset>#include <string>#include <cstdio>#include <cstring>#include <fstream>#include <string.h>#include <iostream>#include <algorithm>#define Si set<int>#define LL long long#define pb push_back#define PS printf(" ")#define Vi vector<int>#define LN printf("\n")#define lson l,m,rt << 1#define rson m + 1,r,rt<<1|1#define SD(a) scanf("%d",&(a))#define PD(a) printf("%d\n",a)#define SET(a,b) memset(a,b,sizeof(a))#define readf freopen("input.txt","r",stdin)#define writef freopen("output.txt","w",stdout)#define FF(i,a) for(int i(0);i<(a);i++)#define FD(i,a) for(int i(a);i>=(1);i--)#define FOR(i,a,b) for(int i(a);i<=(b);i++)#define FOD(i,a,b) for(int i(a);i>=(b);i--)const int maxn = 301;const int INF = ~0U>>1;const int dx[]={0,1,0,-1};const int dy[]={1,0,-1,0};const double pi = acos(-1.0);using namespace std;char a[1001][21];class tire{    public:    int pre;    tire *next[26];    tire(){        pre=0;        SET(next,0);    }}root;void insert(char *word){    tire *p=&root;    int k=0;    while(word[k]!='\0'){        if(!p->next[word[k]-'a'])   p->next[word[k]-'a']=new tire;        p=p->next[word[k]-'a'];        p->pre++;        k++;    }}void query(char *word){    tire *p=&root;    int k=0;    while(word[k]){        if(p->pre==1)   return;        printf("%c",word[k]);        int t=word[k]-'a';        p=p->next[t];        k++;    }}int main(){    int cnt=0;    while(~scanf("%s",a[cnt])){        insert(a[cnt]);        cnt++;    }    FF(i,cnt){        printf("%s ",a[i]);        query(a[i]);        LN;    }    return 0;}