求助大佬们！！

#include<iostream>
using namespace std;
long long s[35][35][35];
long long f(long long a,long long b,long long c)
{
	if(a<=0||b<=0||c<=0)
	{
		return 1;
	}
	else if(a<b&&b<c)
	{
		s[a][b][c]=f(a,b,c-1)+f(a,b-1,c-1)-f(a,b-1,c);
	}
	if(s[a][b][c])return s[a][b][c];
	else
	{
		s[a][b][c]=f(a-1,b,c)+f(a-1,b-1,c)+f(a-1,b,c-1)-f(a-1,b-1,c-1);
	}
	return s[a][b][c];
}
int main()
{
	long long a,b,c;
	while(cin>>a>>b>>c)
	{
		if(a==-1&&b==-1&&c==-1)
		{
			break;
		}
		if(a>20&&b>20&&c>20)
        {
            cout<<"w(20,20,20)";
        }
		cout<<"w("<<a<<","<<b<<","<<c<<")=";
		cout<<f(a,b,c)<<endl;
	}
	return 0;
}