Hi,
I'm new to this community

Wanted to get to know this community better...Since I have been into coding for quite some time, was wondering if any fellow coders out here.

Need help with this dynamic programming problem. Can you guys drop some hints on how do I approach this problem?

Problem:

You are given a set of coins S. In how many ways can you make sum N assuming you have infinite amount of each coin in the set.

Note : Coins in set S will be unique. Expected space complexity of this problem is O(N).

Example:
Input :
S = [1, 2, 3]
N = 4

Return : 4

Explanation : The 4 possible ways are
{1, 1, 1, 1}
{1, 1, 2}
{2, 2}
{1, 3}

Note that the answer can overflow. So, give us the answer % 1000007