codeforces 21A Jabber ID

最新推荐文章于 2023-03-04 11:41:56 发布

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最新推荐文章于 2023-03-04 11:41:56 发布

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本文链接：https://blog.youkuaiyun.com/hyf20144055065/article/details/48275115

本文介绍了一种通过编程方式检查给定字符串是否符合特定JabberID格式的方法。JabberID包括用户名、主机名及可选资源部分，各部分都有严格的字符和长度限制。

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Jabber ID on the national Berland service «Babber» has a form <username>@<hostname>[/resource], where

<username> — is a sequence of Latin letters (lowercase or uppercase), digits or underscores characters «_», the length of <username> is between 1 and 16, inclusive.
<hostname> — is a sequence of word separated by periods (characters «.»), where each word should contain only characters allowed for <username>, the length of each word is between 1 and 16, inclusive. The length of <hostname> is between 1 and 32, inclusive.
<resource> — is a sequence of Latin letters (lowercase or uppercase), digits or underscores characters «_», the length of <resource> is between 1 and 16, inclusive.

The content of square brackets is optional — it can be present or can be absent.

There are the samples of correct Jabber IDs: mike@codeforces.com, 007@en.codeforces.com/contest.

Your task is to write program which checks if given string is a correct Jabber ID.

Input

The input contains of a single line. The line has the length between 1 and 100 characters, inclusive. Each characters has ASCII-code between 33 and 127, inclusive.

Output

Print YES or NO.

Sample test(s)

Input

mike@codeforces.com

Output

YES

Input

john.smith@codeforces.ru/contest.icpc/12

Output

NO

细心，再细心一点！！！！！

 #include<iostream>
 using namespace std;
 #include<string.h>
 int main()
 {
      char s[150];
      int i,k,k1,a[200],s8,j,s1,s2,s3,s4,s5,s6,s7;
      while(cin>>s)
      {k=-1,k1=-1;
      for(i=0;i<strlen(s);i++)
          if(s[i]=='@')k=i;
      if(k==-1||k==strlen(s)-1)cout<<"NO\n";//判断是否有@或@为最后一位
      else
      { if(k<1||k>16)s8=0;
        else s8=1;//判断<username>的大小是否为1~16；
          for(i=k;i<strlen(s);i++)
          if(s[i]=='/'){k1=i;break;}
          for(i=0;i<k;i++)
            if(s[i]>='0'&&s[i]<='9'||s[i]>='A'&&s[i]<='Z'||s[i]>='a'&&s[i]<='z'||s[i]=='_')
                s1=1;
                else  {s1=0;break;}//判断<username>的字符是否正确；
            if(k1==-1)//判断@后面是否存在‘/’；
            {
                if(strlen(s)-k-1>32)
                   s4=0;
                   else s4=1;//判断<hostname>的大小是否为1~32；
                     j=0;s2=1;
                    for(i=k;i<strlen(s);i++)
                        if(s[i]=='.'||s[i]==0||s[i]=='@')
                           a[j++]=i;
                     for(i=0;i<j-1;i++)
                     if(a[i+1]-a[i]-1<1||a[i+1]-a[i]-1>16)
                           s2=0;//判断每两个‘.’之间的字符串大小是否为1~16；
                    for(i=k+1;i<strlen(s);i++)
                         if(s[i]!='.')
                         if(s[i]>='0'&&s[i]<='9'||s[i]>='A'&&s[i]<='Z'||s[i]>='a'&&s[i]<='z'||s[i]=='_')
                              s3=1;
                            else  {s3=0;break;}//判断<hostname>的字符是否正确；
                           s7=1;
                      for(i=k;i<strlen(s);i++)
                    if(s[i]=='.')
                        { if(s[i+1]>='0'&&s[i+1]<='9'||s[i+1]>='A'&&s[i+1]<='Z'||s[i+1]>='a'&&s[i+1]<='z'||s[i+1]=='_')
                               s7=1;
                            else {s7=0; break;}
                        }//判断‘.’后面是否有字符，若无‘.’，则也s7=1;
                       // cout<<s1<<" "<<s2<<" "<<s3<<" "<<s4<<" "<<s7<<" "<<s8<<endl;
                    if(s1&&s2&&s3&&s4&&s7&&s8)cout<<"YES\n";
                    else cout<<"NO\n";

            }
            else
            { int f;
               if(k1-k-1>32)
                   s4=0;
                   else s4=1;//判断<hostname>的大小是否为1~32；
                j=0;s2=1;
               s7=1;
                for(i=k;i<k1;i++)
                    if(s[i]=='.')
                        { if(s[i+1]>='0'&&s[i+1]<='9'||s[i+1]>='A'&&s[i+1]<='Z'||s[i+1]>='a'&&s[i+1]<='z'||s[i+1]=='_')
                               s7=1;
                               else {s7=0; break;}
                        }//判断‘.’后面是否有字符，若无‘.’，则也s7=1;
                    for(i=k;i<k1;i++)
                   if(s[i]=='.'||s[i]==0||s[i]=='@')
                            a[j++]=i;
                     for(i=0;i<j-1;i++)
                     if(a[i+1]-a[i]-1<1||a[i+1]-a[i]-1>16)
                         s2=0;//判断每两个‘.’之间的字符串大小是否为1~16；
                    for(i=k+1;i<k1;i++)
                         if(s[i]!='.')
                         if(s[i]>='0'&&s[i]<='9'||s[i]>='A'&&s[i]<='Z'||s[i]>='a'&&s[i]<='z'||s[i]=='_')
                              s3=1;
                            else  {s3=0;break;}//判断<hostname>的字符是否正确；
                            if(strlen(s)-k1-1<1||strlen(s)-k1-1>16)s5=0;
                            else s5=1;//判断<resource>的大小是否为1~16；
                            for(i=k1+1;i<strlen(s);i++)
                                 if(s[i]>='0'&&s[i]<='9'||s[i]>='A'&&s[i]<='Z'||s[i]>='a'&&s[i]<='z'||s[i]=='_')
                              s6=1;
                            else  {s6=0;break;}//判断<resource>的字符是否正确；
                           // cout<<s1<<" "<<s2<<" "<<s3<<" "<<s4<<" "<<s5<<" "<<s6<<" "<<s7<<" "<<s8<<endl;
                            if(s8&&s1&&s2&&s3&&s4&&s5&&s6&&s7)
                                cout<<"YES\n";
                           else cout<<"NO\n";
            }
      }
      }
     return 0;
 }