10252 - Common permutation/10252.cpp

   1 #include <iostream>
   2 #include <string>
   3 #include <algorithm>
   4 #include <cassert>
   5 using namespace std;
   6
   7 int main(){
   8   string s,t;
   9   while (getline(cin, s) && getline(cin, t)){
  10     //assert(s.find(" ") != string::npos);
  11     //assert(s.length() > 0 && t.length() > 0);
  12     for (int i=0; i<s.size(); ++i){
  13       if (!isalpha(s[i]) || !islower(s[i])){
  14         s.erase(i, 1);
  15         --i;
  16       }
  17     }
  18     for (int i=0; i<t.size(); ++i){
  19       if (!isalpha(t[i]) || !islower(t[i])){
  20         t.erase(i, 1);
  21         --i;
  22       }
  23     }
  24     string r = "";
  25     sort(s.begin(), s.end());
  26     sort(t.begin(), t.end());
  27     //cout << s << endl;
  28     //cout << t << endl;
  29     if (s.size() == 0 || t.size() == 0){
  30       cout << endl;
  31       continue;
  32     }
  33
  34     if (s == t){
  35       cout << s << endl;
  36       continue;
  37     }
  38     for (int i=0, j=0; i < s.size() && j < t.size();){
  39       if (s[i] == t[j]){
  40         r += s[i];
  41         ++i;
  42         ++j;
  43       }else{
  44         while (s[i] < t[j]){
  45           ++i;
  46           if (i == s.size()) break;
  47         }
  48         while (t[j] < s[i]){
  49           ++j;
  50           if (j == t.size()) break;
  51         }
  52       }
  53     }
  54     cout << r << endl;
  55   }
  56   return 0;
  57 }