pascalArray.java

package recursion;

import java.io.BufferedWriter;
import java.io.IOException;
import java.io.OutputStreamWriter;

public class Recursion {

    public static void pascalArray(int[][] matrix) {

        int rows = matrix.length;
        int cols = matrix[0].length;

        for (int i = 2; i < rows; i++) {
            for (int j = 1; j < cols; j++) {
                if (j == 0) {
                    matrix[i][j] = 1;
                    break;
                } else if (j == i) {
                    matrix[i][j] = 1;
                } else {
                    matrix[i][j] = matrix[i - 1][j - 1] + matrix[i - 1][j];
                }
            }
        }
    }

    public static void main(String[] args) throws IOException {
        int size = 20;

        int[][] pascalTest = new int[size][size];

        BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(System.out));
        pascalArray(pascalTest);
        for (int i = 2; i < pascalTest.length; i++) {
            for (int j = 2; j < pascalTest[0].length; j++) {

                writer.write(pascalTest[i][j] + " ");
                if (j == i) {
                    break;
                }
            }
            writer.write("\n");
        }
        writer.flush();
    }
}