JAVA_Printing triangles

Q. Write a program in JAVA to print the following triangles (taking height as command line input from user): 
a. 
1 
2 2 
3 3 3 
4 4 4 4 
b.
1 2 3 4 
1 2 3 
1 2 
1

a:
import java.io.*;
class triangle1
{
public static void main(String args[])
{
int i,j,n;
n=Integer.parseInt(args[0])
for(i=n;i>=1;i--)
{
for(j=1;j<=i;j++)
{
System.out.print(+j);
}
System.out.println( );
}
}
}
Output:
at command line take input 4
1
2  2
3  3  3
4  4  4  4

b:
import java.io.*;
class triangle2
{
public static void main(String args[])
{
int i,j,n;
n=Integer.parseInt(args[0])
for(i=1;i<=1;i++)
{
for(j=1;j<=i;j++)
{
System.out.print(+j);
}
System.out.println( );
}
}
}
Output:
at command line take input 4
1  2  3  4
1  2  3
1  2
1

/*if you have any problem, comment below*/