Question

11.11 LAB: Number pattern Write a recursive function called PrintNumPattern() to output the following number pattern. Given a positive integer as input (Ex: 12), subtract another positive integer (Ex: 3) continually until 0 or a negative value is reached, and then continually add the second integer until the first integer is again reached. For this lab, do not end output with a newline. Ex. If the input is:

Answer 1

void PrintNumPattern(int start, int delta) {

cout << start << " ";

if (start > 0) {

PrintNumPattern(start - delta, delta);

cout << start << " ";

}

}

void main()

{

PrintNumPattern(12, 3);

}

Step-by-step explanation:

Looking at the "palindrome" symmetry of the output, you want one nesting level of the function to print the output twice. Then you also don't need global variables.

Answer 2

The function in C++ is as follows:

int itr, kount;

void printNumPattern(int num1,int num2){

if (num1 > 0 && itr == 0) {

cout<<num1<<" ";

kount++;

printNumPattern(num1 - num2, num2);

} else {

itr = 1;

if (kount >= 0) {

cout<<num1<<" ";

kount--;

if (kount < 0) {

exit(0);}

printNumPattern(num1 + num2, num2);}}

}

Step-by-step explanation:

We start by declaring global variables itr and kount

int itr, kount;

The function is defined here

void printNumPattern(int num1,int num2){

If num1 and itr are greater than 0 , then

if (num1 > 0 && itr == 0) {

Output num1, followed by a space

cout<<num1<<" ";

Increment counter by 1

kount++;

Call the recursion

printNumPattern(num1 - num2, num2);

If otherwise

} else {

Set itr to 1

itr = 1;

If counter is 0 or positive

if (kount >= 0) {

Output num1, followed by a space

cout<<num1<<" ";

Decrease counter by 1

kount--;

If counter is negative

if (kount < 0) {

Exit function

exit(0);}

Call the recursion

printNumPattern(num1 + num2, num2);}}

}