C problem

Question

I wanna write a program which can tell me how many combination it has. here's the problem::One day you go shopping,and the shopkeeper gave you N 💰(such as 100$),but the shopkeeper only provide 1$,5$,20$ three types. How can I write a code to calculate how many ways it has?(If I input 20$,there has 6 combinations)Can anyone give me a hit I would be appreciated! Please

Answer 1

I solved similar logic before. Try this
https://code.sololearn.com/cZ8nhpZ592sH/?ref=app

This may helps you :)