Определить структуру для описания важнейших исторических дат - C++

#include <iostream>
#include <string.h>
using namespace std;
struct GrateDay{
int day_year;
char day_name[80];
GrateDay(){
day_year=0;
strcpy(day_name,"Begin of century");
}
 
GrateDay(const int d, const char *nam){
day_year=d;
strcpy(day_name,nam);
}
 
GrateDay(const GrateDay &rhs){
day_year=rhs.day_year;
strcpy(day_name,rhs.day_name);
}
 
int interval_abs ( const GrateDay &rhs ){
    return (rhs.day_year > day_year) ? rhs.day_year - day_year : day_year - rhs.day_year;
}
 
bool operator<(GrateDay &rhs)const{
return day_year < rhs.day_year;
}
void show()const{
cout<<day_year<<"\t"<<day_name<<endl;
 
}
};
 
template <class Type>
void sort_t(Type *b, int n){
Type a;
for(int i=0; i<n-1; ++i){
int imin=i;
for(int j=i+1; j<n; ++j) if(b[j]<b[imin]) imin=j;
a=b[i];
b[i]=b[imin];
b[imin]=a;
}
}
 
char most_offen_falpha(GrateDay *alotof_grate_days,  int sz ){
 
int *first_alpha = new int[sz];
 
for(int i = 0; i < sz; ++i)first_alpha[i]=alotof_grate_days[i].day_name[0];
sort_t( first_alpha, sz );
char ret = (char)first_alpha[sz-1];
delete first_alpha;
 
return ret;
 
}
 
int main(){
const int sz = 5;
    GrateDay alotof_grate_days[sz];
alotof_grate_days[0]= GrateDay(1863, "Slavership canselation");
alotof_grate_days[1]= GrateDay(1812, "Patriotic Napoleon war");
alotof_grate_days[2]= GrateDay(1917, "Socialist revolution ");
alotof_grate_days[3]= GrateDay(1914, "First Germany war");
alotof_grate_days[4]= GrateDay(1941, "Grate patriotic war");
cout<<"input"<<endl;
for(int i = 0; i < sz; ++i) alotof_grate_days[i].show();
sort_t( alotof_grate_days, sz);
cout<<"sorted"<<endl;
for(int i = 0; i < sz; ++i) alotof_grate_days[i].show();
 
cout<<"The inteval between " <<alotof_grate_days[0].day_name<<" and "<<alotof_grate_days[2].day_name<<endl;
cout<<"is "<<alotof_grate_days[0].interval_abs(alotof_grate_days[2])<<" years"<<endl;
 
cout<<"The inteval between " <<alotof_grate_days[1].day_name<<" and "<<alotof_grate_days[3].day_name<<endl;
cout<<"is "<<alotof_grate_days[1].interval_abs(alotof_grate_days[3])<<" years"<<endl;
 
cout<<"The most offen alpha has met at begin is "<<most_offen_falpha(alotof_grate_days,sz)<<endl;
 
system("pause");
return 0;
}