poj 3630 Phone List

#include<iostream>#include<stdio.h>#include<algorithm>#include<string>#define N 10010using namespace std;string tel[N];bool judge(int n){    int i,k,len;    for(k=0;k<n-1;k++)    {        len=tel[k].size();//<tel[k+1].size()?tel[k].size():tel[k+1].size();        for(i=0;i<len;i++)  if(tel[k][i]!=tel[k+1][i])     break;        if(i==len) return true;    }    return false;}int main(){    int t,i,n;    scanf("%d",&t);    while(t--)    {        scanf("%d",&n);        for(i=0;i<n;i++) cin>>tel[i];        sort(tel,tel+n);        if(judge(n)) printf("NOn");        else printf("YESn");    }    return 0;}