MySTL

#include <hash_map>
#include <cstring>
#include <iostream.h>

using namespace std;
//define the class
struct eqstr {
 bool operator()(const char* s1,const char* s2)
 {
  return strcmp(s1,s2)==0;
 }
};
struct myhash {
 size_t operator()(const char* str)const
 {
  unsigned long __h = 0;  
                for (size_t i = 0 ; i < strlen(str) ; i ++)  
                __h = 5*__h + str[i];  
                return size_t(__h);  
 }
};
int main()
{
        hash_map<const char*,int,myhash,eqstr>  days;
  days["january"]=31;
  days["february"]=28;
  days["march"]=31;
  cout<<days["january"]<<endl;
  cout<<days["february"]<<endl;
  cout<<days["march"]<<endl;
 
        return 0;
}