poj4015之邮箱验证

 

#include<iostream>#include<string>using namespace std;int main(){string s;while(cin>>s){int a=0;int n=1,j,x=0;int i;int t=0,k=0,m,str;str=s.length()-1;for(i=0;i<str;i++){if(s[i]=='@')t++;if(s[i]=='.')k++;if(s[0]=='@'||s[str]=='@'||s[0]=='.'||s[str]=='.')m=0;else m=1;}for(i=0;i<str-1;i++){if((s[i]=='@'&&s[i+1]=='.')||(s[i]=='.'&&s[i+1]=='@')){n=0;    break;}if(s[i]=='@'){for(j=i;j<str;j++)if(s[j]=='.')x++;if(x!=0)a=1;}}int t1=0;int k1=0;if(t==1)t1=1;if(k!=0)k1=1;if(t1&&k1&&n&&a&&m==1)cout<<"YES"<<endl;else cout<<"NO"<<endl;}return 0;}