tridiagonal matrix.cpp

#include<iostream>
using namespace std;

template <class T>
class tridiagonal
{
public:
	tridiagonal(int N=10);
	T get(int ,int )const;
	void set(int,int,T& );
private:
	int n;
	T *arr;;
};
template<class T>
tridiagonal<T> ::tridiagonal(int N)
{
	if(N<1)
		throw ("Matrix size must be  greater than zero");
	n=N;
	arr=new T [n];
}

template <class T>
T tridiagonal<T>:: get(int i,int j)const
{
	if(i<1||j<1||i>n||j>n)
		throw("Array index Out of Bound");

	switch(i-j)
	{
		case 1:
		{
			return arr[i-2];
			break;
		}
		case 0:
		{
			return arr[n+i-2];
			break;
		}
		case -1:
		{
			return arr[2*n+i-2];
			break;
		}
		default:
		{
			return 0;
			break;
		}
	}
}

template <class T>
void tridiagonal<T>::set(int i,int j, T& val)
{
	if(i<1||j<1||i>n||j>n)
		throw("Array index Out of Bound");

	switch(i-j)
	{
		case 1:
		{
			arr[i-2]=val;
			break;
		}
		case 0:
		{
			arr[n+i-2]=val;
			break;
		}
		case -1:
		{
			arr[2*n+i-2]=val;
			break;
		}
		default:
		{
			if(val!=0)
			{
				cout<<"Value should be zero enter again"<<endl;
				cin>>val;
				val=0;
				arr[i]=val;
			}
			break;
		}
	}
}

int main()
{
	int n;int val;
	cout<<"Enter the order of matrix"<<endl;
	cin>>n;int i,j;
	tridiagonal<int> d (n);
	int **arr;
	arr=new int*[n];
	for(int i=1;i<=n;i++)
	{
		arr[i]=new int[n];
	}
	for(int i=1;i<=n;i++)
	{
		for(int j=1;j<=n;j++)
		{
			cout<<"element at position"<<i<<j<<endl; 
			cin>>arr[i][j];
			d.set(i,j,arr[i][j]);
		}
	}
	for(int i=1;i<=n;i++)
	{
		for(int j=1;j<=n;j++)
		{
			cout<<arr[i][j]<<" ";
		}
		cout<<endl;
	}
	int ch;char repeat;
	do
	{
	cout<<"***MENU***"<<endl;
	cout<<"1.Update a element"<<endl;
	cout<<"2.Get an element"<<endl;
	cout<<"Enter your choice"<<endl;
	cin>>ch;
	switch(ch)
	{
		case 1:
		{
			cout<<"Enter the index of the element"<<endl;
			cin>>i>>j;
			cout<<"Enter the value"<<endl;
			cin>>val;
			d.set(i,j,val);
			break;
		}
		case 2:
		{
			cout<<"Enter the position of matrix you want to know the value of"<<endl;
			cin>>i>>j;
			cout<<"The value is "<<d.get(i,j)<<endl;
			break;
		}
		default:
		{
			cout<<"Wrong choice"<<endl;
			break;
		}
	}
	cout<<"Do you want to continue(Y/N)?"<<endl;
	cin>>repeat;
}
	while(repeat=='y'||repeat=='Y');
	
return 0;
}