Source code cây thông

// MERRY Christmas to all

public class XmasTree {

    public static void main(String[] args) {

        int treeHeight = 11;
        int stemHeight = 5;
        int numberOfSpaces = treeHeight - 1;
        int numberOfStars = 1;
        for (int i = 0; i < treeHeight; i++) {
            for (int j = 0; j < numberOfSpaces; j++) {
                System.out.print(" ");
            }
            for (int j = 0; j < numberOfStars; j++) {
                System.out.print("*");
            }
            numberOfSpaces--;
            numberOfStars += 2;
            System.out.println("");
        }
        numberOfSpaces = treeHeight - 2;
        for (int i = 0; i < stemHeight; i++) {
            for (int j = 0; j < numberOfSpaces; j++) {
                System.out.print(" ");
            }
            for (int j = 0; j < 3; j++) {
                System.out.print("*");
            }
            System.out.println("");
        }
    }
}