How to draw Isosceles Triangle in Java using only two for loops? -

i can able draw pattern triangle using 3 for-loops want draw using 2 for-loops.

1   1 2   1 2 3   1 2 3 4   1 2 3 4 5   1 2 3 4 5 6   1 2 3 4 5 6 7   1 2 3 4 5 6   1 2 3 4 5   1 2 3 4   1 2 3   1 2   1  

program of mine 3 loops

import java.util.scanner;  class isotrg {      public static void main(string[] args) {         int n;         system.out.println("enter no. line:");         scanner sc = new scanner(system.in);         n = sc.nextint();          (int = 0; < (2 * n) - 1; i++)         {             int d = 1;             if (i < n)             {                 (int j = 0; j <= i; j++)                 {                     system.out.print(d + " ");                     d++;                 }                 system.out.println();             }             else             {                 for(int j = 1; j < (2 * n) - i; j++)                 {                     system.out.print(d + " ");                     d++;                 }                 system.out.println();             }         }     } } 

your code given doing right steps print triangle correctly. key focus on here stopping condition of loop. when i < n (in case, when i less 7), don't want j exceed i. when i greater n, don't want j exceed 2n - i.

so, considering both of these conditions jointly, want j less i , want less 2n - i. join 2 conditions using logical , operator. you'll have adjust bounds of loop appropriately, checking relative values of i , j @ both ends ensure they're lining appropriately:

public static void main(string[] args) {     int n;     system.out.println("enter no. line:");     scanner sc = new scanner(system.in);     n = sc.nextint();      (int = 1; < (2 * n); i++)     {         (int j = 1; j <= && j <= (2 * n) - i; j++)         {             system.out.print(j + " ");         }         system.out.println();     } } 

additionally, notice can remove unnecessary intermediate variable d.