change(rs) gives the coins required for remaining value

1. change(0) = 0 // we need 0 coins to produce 0 cents
2. change(< 0) = ∞ // in practice, we can return a large positive value
3. change(value) = 1 + min(change(value — coinValue[i])) ∀ i ∈ [0..n-1]

I wrote this but its not working (gives a large integer value !)

#define INT_MA 999999
int memo[1000],v[1000];
int coin(int rs)
{
	if(rs == 0)
		return 0;
	if(rs<0)
		return INT_MA;
	if(memo[rs] != INT_MA)
		return memo[rs];
	int &a = memo[rs];
	for(int i=0;i<n;i++)
	{
		a=min(a,coin(rs-v[i]));
	}
	if(a!=INT_MA)
	a=a+1;
	return a;
}
int main()
{
int n,val;
cin>>n>>val;

for(int i=0;i<n;i++)
cin>>v[i];

memset(memo,INT_MA,sizeof memo);
cout<<coin(val);
}