# Python Program for Print Number series without using any loop

Problem – Givens Two number N and K, our task is to subtract a number K from N until number(N) is greater than zero, once the N becomes negative or zero then we start adding K until that number become the original number(N).
Note : Not allow to use any loop.

Examples :

```Input : N = 15 K = 5
Output : 15 10 5 0 1 5 10 15

Input : N = 20 K = 6
Output : 20 14 8 2 -4 2 8 14 20
```

Explanation – We can do it using recursion idea is that we call the function again and again until N is greater than zero (in every function call we subtract N by K). Once the number becomes negative or zero we start adding K in every function call until the number becomes the original number. Here we use a single function for both addition and subtraction but to switch between addition or subtraction function we used a Boolean flag.

 `# Python program to Print Number ` `# series without using loop ` ` `  `def` `PrintNumber(N, Original, K, flag): ` `    ``#print the number ` `    ``print``(N, end ``=` `" "``) ` `     `  `    ``# change flag if number ` `    ``# become negative ` `     `  `    ``if` `(N <``=` `0``): ` `        ``if``(flag``=``=``0``): ` `            ``flag ``=` `1` `        ``else``: ` `            ``flag ``=` `0` `         `  `    ``# base condition for ` `    ``# second_case (Adding K) ` `     `  `    ``if` `(N ``=``=` `Original ``and` `(``not``(flag))): ` `        ``return` `     `  `    ``# if flag is true ` `    ``# we subtract value until ` `    ``# number is greater then zero ` `     `  `    ``if` `(flag ``=``=` `True``): ` `        ``PrintNumber(N ``-` `K, Original, K, flag) ` `        ``return` `     `  `    ``# second case (Addition ) ` `    ``if` `(``not``(flag)): ` `        ``PrintNumber(N ``+` `K, Original, K, flag); ` `        ``return` `     `  `N ``=` `20` `K ``=` `6` `PrintNumber(N, N, K, ``True``) ` ` `  `# This code is contributed by Mohit Gupta_OMG `

Output :

```20 14 8 2 -4 2 8 14 20
```

Please refer complete article on Print Number series without using any loop for more details!

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