rekurzija dodatni

public class Dodatni {

	static final int nMin = 0, nMax = 35;
	static final int rMin = 5, rMax = 20;

	// rekurzivno preko definicije
	static int fRec1(int n, int r){
		if (n < r) return n - 5;

		else if (gRec1(n-r, r) > 0)
			return fRec1(n-r+1, r) + 3 * fRec1(n-r+2, r) - gRec1(n-r, r);
		else
			return fRec1(n-1, r) + 2 * gRec1(n-2, r) - gRec1(n-r+1, r);
	}

	static int gRec1(int n, int r){
		if (n < r) return (int)Math.pow((4-n), 2);

		else if (n % 2 == 0)
			return 3 * gRec1(n-r+1, r) + fRec1(n-1, r);
		else
			return fRec1(n-r, r) + 2 * gRec1(n-r+2, r);
	}

	//iterativno, efikasno

	static int fItr2(int n, int r) {
		int[] f = new int [r + 1];
		int[] g = new int [r + 1];

		for (int i = 0; i < r; i++){
			f[i] = i - 5;
			g[i] = (int)Math.pow((4-i), 2);
		}

		if (n < r) return f[n];

		else {
			for (int i = r; i <= n; i++){
				if (g[0] > 0)
					f[r] = f[1] + 3 * f[2] - g[0];
				else
					f[r] = f[r-1] + 2 * g[r-2] - g[1];

				if (i % 2 == 0)
					g[r] = 3 * g[1] + f[r-1];
				else
					g[r] = f[0] + 2*g[2];

				for (int j = 0; j < r; j++){
					f[j] = f[j+1];
					g[j] = g[j+1];
				}


			}

		}
		return f[r];
	}




	public static void main (String[] args) {

		int n;
		do
		{
			n = Svetovid.in.readInt("Unesite broj n: ");
		} while (!(n < nMin || n < nMax));

		int r;
		do
		{
			r = Svetovid.in.readInt("Unesite broj r: ");
		} while (!(r < rMin || r < rMax));

		System.out.println("fRec1: " + fRec1(n, r));
		System.out.println("fItr2: " + fItr2(n, r));


		/* for (int i = nMin; i <= nMax ; i++){
			for (int j = rMin; j <= rMax; j++){
				System.out.println("i = " + i + "j= " + j + "Def: " + fRec1(i, j));

			}

		} */



	}
}