一个STL问题

Question

#include<list>
#include<iostream>
#include <algorithm>
#include <functional> 

#if _MSC_VER > 1020
using namespace std;
#endif

int main()
{
 list<int> c1,c2,c3;
 list<int>::iterator c1_Iter,c2_Iter,c3_Iter;
 c1.push_back(3);
 c1.push_back(6);
 c2.push_back(2);
 c2.push_back(4);
 c3.push_back(5);
 c3.push_back(1);
 
 cout<<"c1 = ";
 for(c1_Iter = c1.begin();c1_Iter != c1.end();c1_Iter++)
  cout<<" "<<*c1_Iter;
 cout<<endl;
 cout<<"c2 = ";
 for(c2_Iter = c2.begin();c2_Iter != c2.end();c2_Iter++)
  cout<<" "<<*c2_Iter;
 cout<<endl;
  c2.merge(c1);
  cout<<"After merging c1 with c2 and sorting with>: c2 = ";
 for(c2_Iter = c2.begin();c2_Iter != c2.end();c2_Iter++)
  cout<<" "<<*c2_Iter;
 cout<<endl;
 cout<<"c3 = ";
 for(c3_Iter = c3.begin();c3_Iter != c3.end();c3_Iter++)
  cout<<" "<<*c3_Iter;
 cout<<endl;
 c2.merge(c3,greater<int>());

 cout<<"After merging c3 with c2 according to the '>' comparison relation: c2 = ";
 for(c2_Iter = c2.begin();c2_Iter != c2.end();c2_Iter++)
  cout<<" "<<*c2_Iter;
 cout<<endl;
 
 ::getchar();
 return 0;
}

 

上面得代码在Debug下 调试 报了一个assert的错误，在release下调试通过。不知道该怎么改，或者需不需要该