LowerTriangle.cpp

#include <iostream>
using namespace std;

class LowerTriangle
{
private:
 int *A;
 int n;
public:
 LowerTriangle()
 {
   n = 2;
   A = new int[2 *(2+1) / 2];
 }
 LowerTriangle(int n)
 {
   this->n=n;
   A=new int[n*(n+1)/2];
 }
 ~LowerTriangle()
 {
   delete []A;
 }
 void Set(int i,int j,int x);
 int Get(int i,int j);
 void Display();
 int GetDimension(){return n;}
};
void LowerTriangle::Set(int i,int j,int x)
{
 if(i>=j)
  A[i*(i-1)/2 + j-1]=x;
}
int LowerTriangle::Get(int i,int j)
{
 if(i>=j)
  return A[i*(i-1)/2 + j-1];
 return 0;
}
void LowerTriangle::Display()
{
 for(int i=1;i<=n;i++)
 {
 for(int j=1;j<=n;j++)
 {
 if(i>=j)
  cout<<A[i*(i-1)/2 + j-1]<<" ";
 else
  cout<<"0 ";
 }
 cout<<endl;
 }
}

int main()
{
 int d;
 cout<<"Enter Dimensions";
 cin>>d;

 LowerTriangle lowerTriangle(d);

 int x;
 cout<<"Enter All Elements";
 for(int i=1;i<=d;i++)
 {
 for(int j=1;j<=d;j++)
 {
 cin>>x;
 lowerTriangle.Set(i,j,x);
 }
 }

 lowerTriangle.Display();
 return 0;
}