pattern-without-loop.cpp

// C++ program to print pattern that first reduces 5 one
// by one, then adds 5. Without any loop
#include <iostream>
using namespace std;

// Recursive function to print the pattern.
// n indicates input value
// m indicates current value to be printed
// flag indicates whether we need to add 5 or
// subtract 5. Initially flag is true.
void printPattern(int n, int m, bool flag)
{
	// Print m.
	cout << m << " ";
	
	// If we are moving back toward the n and
	// we have reached there, then we are done
	if (flag == false && n ==m)
		return;
	
	// If we are moving toward 0 or negative.
	if (flag)
	{
	// If m is greater, then 5, recur with true flag
	if (m-5 > 0)
		printPattern(n, m-5, true);
	else // recur with false flag
		printPattern(n, m-5, false);
	}
	else // If flag is false.
		printPattern(n, m+5, false);
}


void PrintPattern(int m)
{
	if (m > 0)
	{
		cout << m << '\n';
		PrintPattern(m - 5);
	}

	cout << m << '\n';
}

int main()
{
	int n = 16;
	//printPattern(n, n, true);
	PrintPattern(n);
	return 0;
}