Question

As a seasonal amusement some programmers like to print out a picture of a Christmas Tree looking like this.

*
***
*
***
*****
*
***
*****
*******
|
---+---

The tree consists of a series of tiers (three in this case) of increasing size. Write a program to produce such a display having prompted the user for thw number of tiers. You could try a few baubles on the tree (using o or O).

Answer 1

What language are you writing in, what have you already tried, and what is giving you difficulties?

Answer 2

I'm using C language..!! I have no difficulties with the language itself..!! It's the logic that I lack..!! :P ..!!
I just can't figue out how to use loops to achieve the wanted result..!!
Can you help me with that..??
:)..!!

Answer 3

print characters
3 characters next time 5 characters .. 7 ... etc etc

Answer 4

i haven't programmed C for very long time. do something like this

for(i=1;i<= 3, i++)
{
for(k=2i+1; k >= 1; k++)
{
for(j=1; j<= 2i+1)
{
print on center here
}
}
}

Answer 5

@eSpeX
That's how tried doing it the first time using while loop :

n = number of tiers

while(n!=0)
{
printf( * \n)
printf(O***O\n)
n--
while(n!=0)
{
printf( * \n)
printf( *** \n)
printf( ***** \n)
n--
}
while(n!=0)...and so on..!!
}

But then it's kind of an infinite thing..!!

..@experimentX Thank you..!! However I don't really understand how it works..!!

Answer 6

i don't seem to have c compiler in my computer .. mind if I send you python code?

Answer 7

I'll try to decode it back to C..!! :P ..!! So don't worry..!! :) ..!!

Answer 8

i ended up codig this in java
public class Christmas{
public static void main(String args[]){
int i, j, k;
for(i=1; i <= 3; i++){
for(j=i+1; j>=1; j--){
for(k=1; k<=2*i+1; k++){
if(k >= j && k <= -j + 2*(i+1))
System.out.print("*");
else
System.out.print(" ");
}
System.out.println("");
}
}
}
}

Answer 9

still not working

Answer 10

this is the working code in Java

public class Christmas{
public static void main(String args[]){
int i, j, k, l=3;
for(i=1; i <= l; i++){
for(j=i+1; j>=1; j--){
for(int x=1; x<=l-i; x++)
System.out.print(" ");
for(k=1; k<=2*l+1; k++){
if(k >= j && k <= -j + 2*(i+1))
System.out.print("*");
else
System.out.print(" ");
}
System.out.println("");
}
}
}
}

Answer 11

The logic is that you want to build i triangles of heights j = 2, 3, 4, ... with row lengths k = 1, 3, 5, 7.... So you use nested for loops (go backwards starting with k).

Answer 12

(Because you have to center it, it's important to note that the widest part of the tree should be 2*i+1)