package Maths;

/**
 * The trinomial triangle is a variation of Pascal’s triangle. The difference
 * between the two is that an entry in the trinomial triangle is the sum of the
 * three (rather than the two in Pasacal’s triangle) entries above it
 * 
 * Example Input: n = 4 
 * Output 
 * 1 
 * 1 1 1 
 * 1 2 3 2 1 
 * 1 3 6 7 6 3 1
 */
public class TrinomialTriangle {

 public static int TrinomialValue(int n, int k) {
 if (n == 0 && k == 0) {
 return 1;
 }

 if (k < -n || k > n) {
 return 0;
 }

 return TrinomialValue(n - 1, k - 1) + TrinomialValue(n - 1, k) + TrinomialValue(n - 1, k + 1);
 }

 public static void printTrinomial(int n) {
 for (int i = 0; i < n; i++) {
 for (int j = -i; j <= 0; j++) {
 System.out.print(TrinomialValue(i, j) + " ");
 }

 for (int j = 1; j <= i; j++) {
 System.out.print(TrinomialValue(i, j) + " ");
 }

 System.out.println();
 }
 }

 public static void main(String argc[]) {
 int n = 6;
 printTrinomial(n);
 }
}