RE求调

#include <iostream>
using namespace std;
bool flag[30][30][30] = { 0 };
long long sum[30][30][30] = { 0 };
long long W(long long a, long long b, long long c)
{
	sum[0][0][0] = 1;
	if (a <= 0 || b <= 0 || c <= 0)
	{
		flag[0][0][0] = 1;
		return 1;
	}
	else if (a > 20 || b > 20 || c > 20)
	{
		flag[20][20][20] = 1;
		sum[20][20][20] = W(20, 20, 20);
	}
	else if (a < b && b < c)
	{
		if (!flag[a][b][c - 1])
		{
			flag[a][b][c - 1] = 1;
			sum[a][b][c - 1] = W(a, b, c - 1);
		}
		if (!flag[a][b - 1][c])
		{
			flag[a][b - 1][c] = 1;
			sum[a][b - 1][c] = W(a, b - 1, c);
		}
		if (!flag[a][b - 1][c - 1])
		{
			flag[a][b - 1][c - 1] = 1;
			sum[a][b - 1][c - 1] = W(a, b - 1, c - 1);
		}
		sum[a][b][c] = sum[a][b][c - 1] + sum[a][b - 1][c - 1] - sum[a][b - 1][c];
	}
	else
	{
		if (!flag[a - 1][b][c - 1])
		{
			flag[a - 1][b][c - 1] = 1;
			sum[a - 1][b][c - 1] = W(a - 1, b, c - 1);
		}
		if (!flag[a - 1][b - 1][c])
		{
			flag[a - 1][b - 1][c] = 1;
			sum[a - 1][b - 1][c] = W(a - 1, b - 1, c);
		}
		if (!flag[a - 1][b][c])
		{
			flag[a - 1][b][c] = 1;
			sum[a - 1][b][c] = W(a - 1, b, c);
		}
		if (!flag[a - 1][b - 1][c - 1])
		{
			flag[a - 1][b - 1][c - 1] = 1;
			sum[a - 1][b - 1][c - 1] = W(a - 1, b - 1, c - 1);
		}
		sum[a][b][c] = sum[a - 1][b][c - 1] + sum[a - 1][b - 1][c] + sum[a - 1][b][c] - sum[a - 1][b - 1][c - 1];
	}
	return sum[a][b][c];
}
int main()
{
	while (true)
	{
		long long u, v, w;
		cin >> u >> v >> w;
		if (u == -1 && v == -1 && w == -1)
		{
			break;
		}
		cout << "w(a, b, c) = " << W(u, v, w) << endl;
	}
	return 0;
}