Given a list of phone numbers, determine if it is consistent in the sense that no number is the PRefix of another. Let's say the phone catalogue listed these numbers:
Emergency 911Alice 97 625 999Bob 91 12 54 26In this case, it's not possible to call Bob, because the central would direct your call to the emergency line as soon as you had dialled the first three digits of Bob's phone number. So this list would not be consistent.
输入The first line of input gives a single integer, 1 ≤ t ≤ 10, the number of test cases. Each test case starts with n, the number of phone numbers, on a separate line, 1 ≤ n ≤ 100000. Then follows n lines with one unique phone number on each line. A phone number is a sequence of at most ten digits.输出For each test case, output "YES" if the list is consistent, or "NO" otherwise.样例输入2391197625999911254265113123401234401234598346样例输出NOYES解题报告：用字典树
code：
#include<iostream>#include<stdio.h>#include<queue>#include<vector>#include<stack>#include<cstring>#include<algorithm>using namespace std;typedef long long ll;const int maxn=100005;const int MAX=10;typedef struct node{ struct node *next[MAX]; int flag; //标记是否是一个单词}Trie;Trie *root;/*root要初始化root=(Trie *)malloc(sizeof(Trie));root->flag=0;for(int i=0;i<MAX;i++){ root->next[i]=NULL;}*/int createTrie(char *str) //创建一棵字典树,与查找合并{ int len = strlen(str); Trie *p = root, *q; for(int i=0; i<len; i++) { if(p->flag==1) //查找1；说明已有一个单词作为前缀,比如119,119895 return 1; int id = str[i]-'0'; //数字字符 if(p->next[id] == NULL) { q = (Trie *)malloc(sizeof(Trie)); q->flag = 0; //初始v==1 for(int j=0; j<MAX; j++) q->next[j] = NULL; p->next[id] = q; } p = p->next[id]; } for(int i=0;i<MAX;i++){ //查找2；判断该单词是否是其它单词的前缀，如119895，119 if(p->next[i]!=NULL) return 1; } p->flag=1; //一个单词 return 0;}void dealTrie(Trie* T) //清理内存root{ for(int i=0;i<MAX;i++) { if(T->next[i]!=NULL) dealTrie(T->next[i]); } free(T);}int main(){ // freopen("input.txt","r",stdin); int t,n; scanf("%d",&t); while(t--){ root=(Trie *)malloc(sizeof(Trie)); //初始化 root->flag=0; for(int i=0;i<MAX;i++){ root->next[i]=NULL; } scanf("%d",&n); int flag=1; //默认YES char s[15]; for(int i=0;i<n;i++){ getchar(); scanf("%s",s); if(!flag) //把数据读完 continue; if(createTrie(s)){ flag=0; } } if(flag) printf("YES/n"); else printf("NO/n"); dealTrie(root); //释放内存，否则超内存 } return 0;}
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