Day52.java

import java.util.ArrayList;
import java.util.List;

public class Day52 {

    public List<List<Integer>> generate(int numRows) {
        List<List<Integer>> triangle = new ArrayList<>();
        
        if (numRows == 0) {
            return triangle;
        }
        
        List<Integer> firstRow = new ArrayList<>();
        firstRow.add(1);
        triangle.add(firstRow);
        
        for (int i = 1; i < numRows; i++) {
            List<Integer> prevRow = triangle.get(i - 1);
            List<Integer> row = new ArrayList<>();
            
            row.add(1);
            
            for (int j = 1; j < i; j++) {
                row.add(prevRow.get(j - 1) + prevRow.get(j));
            }
            
            row.add(1);
            
            triangle.add(row);
        }
        
        return triangle;
    }

    public static void main(String[] args) {
        int N = 4;
        PascalTriangle pascalTriangle = new PascalTriangle();
        List<List<Integer>> result = pascalTriangle.generate(N);
        
        // Print the result
        for (List<Integer> row : result) {
            for (Integer num : row) {
                System.out.print(num + " ");
            }
            System.out.println();
        }
    }
}