如何使方法根据传入的参数在一定时间内执行某些操作？

Question

public void printStars(int level) {

    for (int one = level; one >= 1; one--) {

        for (int two = one; two <= level; two++) {


            System.out.print("*");

        }
        System.out.println();


    }
}

I am trying to make something that looks like this:

    *
   ***
  *****
 *******
*********

Currently I am getting about half of the correct diagram all left aligned.

I tried to incorporate printf, but I realized that it wouldn't work because the value of level cannot be transferred to the printf method. I was also wondering if there was a way to set the longest segment (the bottom) equal to (2 * level) - 1 stars long and apply some sort of formatting on that to get the answer?

Answer 1

Print appropriate number of spaces ahead

public void printStars(int level) {

    for (int one = level; one >= 1; one--) {
        for(int k=1, k<one;k++){  // print appropriate number of spaces before
            System.out.print(" "); 
        }    
        for (int two = 1; two <=2*(level-one)+1; two++) {
            System.out.print("*");
        }
        System.out.println();
    }
}

Explanation:

1. if there are N levels in total, and last line doens't have any space. => N-1 levels will have spaces with N-1 in first line, N-2 in 2nd line, so on.. 1 in (N-1)th line.

2. Number of stars: (level-one) gives the line you are printing minus 1, because, initially when one = level (one-level = 0), its 1st line, next its (level-one) = 1, because one is decreased. & in each line you have to print, 2*X +1 *'s,

Answer 2

Try below:

public static void printStars(int level) {
    for (int one = 0; one < level; one++) {
      for(int space = 1; space < (level-one); space++){ //<- print leading space
       System.out.print(" ");
      }

      //<- print stars in odd numbers e.g. 1,3,5,7
      for (int two = 0; two < 2*one+1; two++) { 
       System.out.print("*");
      }
      System.out.println();
   }
 }