All C-C++ programs

#include<stdio.h>
long int fect(long int);
int main(){
long int i,r,j,k=0;
long int n;
printf("\nEnter last number :");
scanf("%d",&r);
for(i=1;i<=r;i++){
    for(k=0;k<=r-i-1;k++)
    printf(" ");

for(j=1;j<=i;j++){
n=fect(i)/(fect(j)*fect(i-j));
printf("%ld ",n);
}
printf("\n");
}


return 0;
}
long int fect(long int n){
long int i,j,sum=1;
for(i=n;i>0;i--)
sum*=i;
return sum;
}

C++

#include<iostream>
#include<cstring>
using namespace std;
class A{
public :
int l,m;
int age;
char name[20];
A(){

age=0;

}
void geta();
void printa();
};
class C:public A{
public:
void getc();
void printc();

};

class B:public C {
public :
void getb();
void printb();

};
void A::geta(){
cout<<"\nEnter name:";
cin>>name;
cout<<"\nEnter age";
cin>>age;
}
void A::printa()
{
    cout<<"name and age:";
    cout<<name<<age;
}

void C::getc(){
cout<<"\nEnter name:";
cin>>name;
cout<<"\nEnter age";
cin>>age;
}
void C::printc()
{
    cout<<"name and age:";
    cout<<name<<age;
}

void B::getb(){
cout<<"\nEnter name:";
cin>>name;
cout<<"\nEnter age";
cin>>age;
}
void B::printb()
{
    cout<<"name and age:";
    cout<<name<<age;
}


int main(){
A obj;
A *ptr;
ptr=&obj;
//ptr->i=300;
ptr->geta();
ptr->printa();

C objc;
ptr=&objc;
((C *)ptr)->getc();
(( C *)ptr)->printc();


B objb;
ptr=&objb;
(( B*)ptr)->getb();
(( B *)ptr)->printb();

return 0;
}

GCD

#include<stdio.h>
int main(){
int i,a,b,n;
printf("\nEnter a and b:");
scanf("%d%d",&a,&b);
for(i=2;i<a;i++){
if(a%i==0 && b%i==0){
   n=i;
break;
}else
n=1;
}
printf("GCD is :%d",n);
return 0;
}