hdu1671 Phone List

#include <iostream>
#include <stdio.h>
#include <string.h>
#include <math.h>
#include <stdlib.h>
#include <algorithm>
#include <vector>
#include <limits.h>
#include <queue>
#include <stack>
using namespace std;
struct trie
{
int is;
trie* next[11];
};

char ch[11];
int ans;
void inst(trie *root,char* s)
{
trie *p = root;
int i = 0,len = strlen(s),f = 1,ff=1;
//cout<<s<<endl;
while(i < len)
{
//cout<<i<<endl;
int k = s[i]-'0';
if(p->next[k] == NULL)
{
//cout<<i<<endl;
trie* tmp = new trie;
//cout<<i<<endl;
for(int j= 0;j < 11;j ++) tmp->next[j] = NULL;
tmp->is = 0;
p->next[k] = tmp;
}
else
{
if(p->next[k]->is == 1) f = 0;
}

p = p->next[k];
i ++;
}
p->is = 1;
for(i = 0;i < 11;i ++) if(p->next[i]!=NULL) ff = 0;
if(f&&ff) ans ++;
}
void del(trie *root)                    //释放空间
{
for(int i=0;i<11;i++)
{
if(root->next[i]!=NULL)
{
del(root->next[i]);
}
}
delete root;
}
int main()
{
int t,n;
//cin>>t;
scanf("%d",&t);

while(t --)
{
trie *root = new trie;
scanf("%d",&n);
ans = 0;
for(int i = 0;i < 11;i ++) root->next[i] = NULL;
for(int i = 0;i < n;i ++)
{
scanf("%s",ch);
inst(root,ch);
}

//sort(s,s+n,cmp);
//cout<<ans<<endl;
if(ans == n) printf("YES\n");
else printf("NO\n");
del(root);
}

}