UVa/11371 - Number theory for newbies/11371.cpp

   1 #include <iostream>
   2 #include <algorithm>
   3 #include <vector>
   4 #include <cassert>
   5
   6 using namespace std;
   7
   8 int main(){
   9   string s;
  10   while (getline(cin, s)){
  11     assert(s[0] != '0');
  12     vector<int> v(s.size());
  13     for (int i=0; i<s.size(); ++i) v[i] = s[i] - '0';
  14     sort(v.begin(), v.end(), greater<int>() );
  15
  16     long long int a = 0;
  17     for (int i=0; i<v.size(); ++i){
  18       a*= 10; a += v[i];
  19     }
  20
  21     sort(v.begin(), v.end());
  22     if (v[0] == 0)
  23       for (int i=1; i<v.size(); ++i){
  24         if (v[i] != 0){
  25           swap(v[0], v[i]);
  26           break;
  27         }
  28       }
  29
  30     long long int b = 0;
  31     for (int i=0; i<v.size(); ++i){
  32       b*= 10; b += v[i];
  33     }
  34
  35     printf("%lld - %lld = %lld = 9 * %lld\n", a, b, a-b, (a-b)/9);
  36
  37   }
  38   return 0;
  39 }