#include <iostream>
#include <map>
 
using namespace std;
int main ()
{
  map<char,int> MapFirst;
  map<char,int> MapSecond;
 
  MapFirst['a']=1;
  MapFirst['b']=2;
 
  MapSecond['z']=23;
  MapSecond['y']=22;
 
  cout << "MapFirst keeps before swap:  MapSecond keeps before swap:" << endl;
  auto itMapFirst=MapFirst.begin();
  auto itMapSecond=MapSecond.begin();
  for(itMapFirst,itMapSecond; itMapFirst != MapFirst.end(); ++itMapFirst,++itMapSecond)
  {
      cout << itMapFirst->first << " : " << itMapFirst->second << "\t\t\t\t\t"
      << itMapSecond->first << " : " << itMapSecond->second <<endl;
  }
 
  swap(MapFirst,MapSecond);///обмен
 
  cout << "MapFirst keeps after swap:    MapSecond keeps after swap:" << endl;
  itMapFirst=MapFirst.begin();
  itMapSecond=MapSecond.begin();
  for(itMapFirst,itMapSecond; itMapFirst != MapFirst.end(); ++itMapFirst,++itMapSecond)
  {
      cout << itMapFirst->first << " : " << itMapFirst->second << "\t\t\t\t\t"
      << itMapSecond->first << " : " << itMapSecond->second <<endl;
  }
 
  MapFirst.swap(MapSecond);///обмен
 
  cout << "MapFirst keeps after anoter swap:    MapSecond keeps after anoter swap:" << endl;
  itMapFirst=MapFirst.begin();
  itMapSecond=MapSecond.begin();
  for(itMapFirst,itMapSecond; itMapFirst != MapFirst.end(); ++itMapFirst,++itMapSecond)
  {
      cout << itMapFirst->first << " : " << itMapFirst->second << "\t\t\t\t\t"
      << itMapSecond->first << " : " << itMapSecond->second <<endl;
  }
 
  return 0;
}

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