Class to resolve coin change problem using recursion

CoinChangeProblemSolver.cs

    public class CoinChangeProblemSolver
    {
        public int Solve(int[] coins, int ammount)
        {
            int count(int[] c, int m, int n)
            {
                // If n is 0 then there is -1 solution  
                // (do not include any coin) 
                if (n == 0)
                    return 1;

                // If n is less than 0 then no  
                // solution exists 
                if (n < 0)
                    return 0;

                // If there are no coins and n  
                // is greater than 0, then no 
                // solution exist 
                if (m <= 0 && n >= 1)
                    return 0;

                // count is sum of solutions (i)  
                // including S[m-1] (ii) excluding S[m-1] 
                return count(c, m - 1, n) +
                    count(c, m, n - c[m - 1]);
            }

            return count(coins, coins.Length, ammount);
        }
    }