代码

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
int n,m;
map<string,int>mp;
int getlen(int x){
    int len=0;
    if(x==0)return 1;
    while(x){
        x/=10;
        len++;
    }
    return len;
}
bool check(string s){
    string tmp="";
    int num=0,cnt=0;
    for(int i=0;i<s.size();i++){
        if(s[i]>='0'&&s[i]<='9'){
            num=num*10+s[i]-'0';
            cnt++;
        }
        else {
            if(cnt==0||cnt>=4||num>255||getlen(num)!=cnt){
                return 0;
            }
            tmp+=s[i],num=cnt=0;
        }
    }
    if(tmp=="...:"&&cnt>0&&cnt<6&&num<65535&&getlen(num)==cnt)
        return 1;
    else return 0;
}
int main(){
    cin>>n;
    string s,t;
    for(int i=1;i<=n;i++){
        cin>>s>>t;
        if(!check(t)){
            cout<<"ERR"<<endl;
            continue;
        }
        if(s=="Server"){
            if(mp[t]){
                cout<<"FAIL"<<endl;
            }
            else {
                cout<<"OK"<<endl;
                mp[t]=i;
            }
        }
        else {
            if(mp[t]){
                cout<<mp[t]<<endl;
            }
            else {
                cout<<"FAIL"<<endl;
            }
        }
    }
    return 0;
}