Currently doing the CS-50 course and was wondering if anyone could help me with this. I'm supposed to create a program which will ask a user for a height between 1-23 (and continuously prompt the user until a valid answer is given) --- I was able to code that part.
#include <cs50.h>
#include <stdio.h>
int main(void)
{
int height;
do
{
printf("please give me a height between 1-23: ");
height = GetInt();
}
while (height < 1 || height > 23);
}
The do while loop seems to do what its intended. Now, the program, given the variable "height" now needs to create a pyramid of that height. The bottom of the pyramid is to be aligned with the bottom left hand of the terminal and its last "row" is to finish with 2 hashes as such:
Sample pyramid of height 4:
##
###
####
#####
But the code needs to be generic for any height of pyramid 1-23.
This is where I'm having a hard time (in actually making a code to draw this).
Ive noticed that for each row, the number of hashes needed (if we call the top row "row 1" and the subsequent "row 2" and so on... is
row number+1. As for the amount of spaces that are needed, can be represented by height-row number.
If someone would be able to explain to me how I could write this program using C, it would be much appreciated! :)
Here is a way you can implement this. Basically, you need to build the pyramid from the bottom up. The task is easy once you see the loop structure, its just tricky to get the math down for printing the correct number of spaces and hash symbols:
#include <stdio.h>
int main(void)
{
int height, i, j;
do
{
printf("please give me a height between 1-23: ");
height = GetInt();
}
while (height < 1 || height > 23);
printf("\n");
for (i = 0; i < height; i++) {
for (j = 0; j < height - i - 1; j++)
printf(" ");
for (j = 0; j < i + 2; j++)
printf("#");
printf("\n");
}
}
For more clarification on whats going on, and why each loop is necessary:
Outer for loop: the variable i corresponds to a row in the pyramid. the value of i will remain constant for each of the second two loops
First inner for loop: for any row, there needs to be height - i - 2 spaces. You can figure this out because the total row width will be height, and any row has i + 2 hash symbols, so there needs to be height - (i + 2) = height - i - 1 spaces. So basically, this loop just prints the required spaces. You can track this with the variable j
Second inner for loop: This loop is similar to the first inner loop, but you need to now print the hash marks. At the beginning of the loop you reset j and count up to the required number of hash marks
Here is a version that may offer some insight:
#include <stdio.h>
#include <cs50.h>
int main(void) {
//initialize variables
int height, n, j, k, i;
printf("Height: \n");
// Get user input
height = GetInt();
n = height;
for(i = 0; i < height; i++) {
// create n spaces based off height
for(k = n; k > i; k--)
printf("%c", ' ');
// create hash tags
for(j = 0; j < i+2; j++)
printf("#");
printf("\n");
}
return 0;
}
Result if user entered a height of 5:
Height:
##
###
####
#####
######
The 1st for loop essentially prints the number of rows matching the height entered
The 2nd for loop involves printing the number of spaces based on the height entered
The 3rd for loop involves printing the number of hashes (with respect to the height value) after the amount of spaces on the same line
Cheers
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How do I check out a remote Git branch?
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Closed 1 year ago.
I just started with C programming and have some difficulty implementing a program which is giving a staircase with 'Height' amount of steps.
#include <cs50.h>
#include <stdio.h>
int main(void)
{
int height;
do
{
height = get_int("Height: ");
}
while(height > 8 || height == 0 || height < 0);
int width = 0;
int length = height;
while(width < height)
{
printf(" ");
printf("#");
for(width = 0; width < height; width++)
{
printf("\n");
}
}
}
The first lines with the Height are working, but I have difficulties with actually writing a staircase. I wanted something like this or similar to this.
Height: 3
#
#
#
I just want to learn how to implement something like this if I face a problem like this in the future. If somebody could help me further I would really appreciate it!
This works:
#include <stdio.h>
int main() {
// gets height input - replace with your get_int method
int height;
printf("Height: ");
scanf("%i",&height);
// loop over all the steps: 0 - height
for (int i = 0; i < height; i++) {
// add a space i number of times (where i is our current step number and so equal to width)
// notice that if we take top left as (0,0), we go 1 down and 1 right each time = current step
for (int j = 0; j < i; j++) {
printf(" ");
}
// finally, after the spaces add the character and newline
printf("#\n");
}
return 0;
}
I see three issues here:
You're printing newlines (\n) instead of spaces ( ).
Why print the single space character?
You're printing the "#" before (what should be) the spaces.
Print a newline after the spaces and the #.
Also... the staircase's width is always equal to its height; it's just the line you're printing that's advancing... that's a bit confusing.
#include <stdio.h>
int main(void)
{
int height = 5;
for(int i=0; i<height; printf("%*s\n", ++i, "#"));
}
Output:
Success #stdin #stdout 0s 5572KB
#
#
#
#
#
Here is a copy of my code:
#include <cs50.h>
#include <stdio.h>
int main(void)
{
int height = get_int("Please enter a height between 1 and 8 (inclusive)\nHeight: ");
if(0 < height && height < 9)
for(int i = 0; i <= height; i++)
{
for(int s = (height - 1); s >= 1; s--)
{
printf("a");
}
for(int h = 1; h <= i; h++)
{
printf("#");
}
printf("\n");
}
else
printf("Please try again.\n"),
main();
}
The part I cannot seem to get right is printing the correct number of spaces as it does not seem to reduce the variable "s" after each loop. (I have replaced the spaces with the letter "a" so I can see where the code has gone wrong.)
The aim of the code is to print a pyramid of #'s that is right-aligned.
Where have I gone wrong here?
So for example, if the user inputs a height of 3, the output will be:
aa
aa#
aa##
aa###
however, I would like the output to be:
aa#
a##
###
The main issue is the 2nd for loop in your code when you print "a". Everytime you hit in this particular loop, you basically print (height - 1) times "a". In fact, you should print every time one less "a" (and one more hashes). To achieve this, we need to tweak condition of s.
Instead of this
int s = height - 1; s >= 1
Use this
int s = height - i; s > 1
Since your main loop has iterator i, we can use it here.
Second issue is that according to CS50 problem set description, you should actually print " " (spaces), not "a". For this, you should replace "a" with " ".
Third issue is your code prints an extra line with full of space in the begining. You need to tweak the main for loop with this condition to remove one extra line.
i < height
And in the for loop where you print # symbol, you need to start iterator h from zero, so that it prints right away with the first line.
int h = 0
The better solution is to use the built-in functionality of printf that is already in place, reducing the problem to a single, simple loop.
#include <stdio.h>
int main(void) {
int height = get_int("Please enter a height between 1 and 8 (inclusive)\nHeight: ");
unsigned char blocks[height];
memset(blocks, '#', height);
for(int i=0; i<height; ++i)
{
printf("%*.*s\n", height, i+1, blocks);
}
return 0;
}
Output
Success #stdin #stdout 0s 4212KB
#
##
###
####
#####
I'm currently going through CS50 through edx and doing problem set 1, Mario.
The objective is to create a print out using pound signs. With the help of some videos I got the code for the first one but I don't understand fundamentally how the math works/ what the computer is understanding.
So I figure if I don't learn I'm crippling myself later.
if n= 5
Then i has 1 added to it until it is not less than 5 which means 5 times yes?
Take a look at this line for the space loop >
for (int j = 0; j < n -1 - i; j++)
If n is 5, then it ends up being j(0) < 3...
So why on the first line are there four spaces and not three spaces?
#include <cs50.h>
#include <stdio.h>
int main(void)
{
int n;
do
{
n = get_int("Pyramid Height: ");
}
while (n < 0 || n >= 24);
//print out this many rows
for (int i = 0; i < n; i++)
{
for (int j = 0; j < n -1 - i; j++)
{
printf(" ");
}
// print out this many columns
for (int j = 0; j < i + 2; j++)
{
printf("#");
}
printf("\n");
}
}
I get the correct pyramid yet i don't understand the logic behind the spacing and prints
if n=5 then n-1-j would be equal 5-1-0 i.e. 4 for the first time executing the loop that is the reason why you are seeing four spaces. The first loop condition should be n-2-j if you want the number of spaces to be three because total no of columns is 5 and the pounds expected in the first row are 2, therefore you should be subtracting 2 from n.
That looks way too complicated.
Here's a simple version I whipped up:
#include <stdio.h>
int main(void) {
int height = 5;
char blocks[height];
memset(blocks,'#',height);
for(int i=0; i<height; ++i)
{
printf("%*.*s\n", height, i+1, blocks );
}
return 0;
}
Output:
Success #stdin #stdout 0s 9424KB
#
##
###
####
#####
Let us try to figure out the pattern here. Like for the left pyramid if the height of the pyramid is 8, check the pattern of spaces and hashes from top to bottom. In this case we need 8 lines, every line has same characters and no of spaces decreases and no of hashes increases from top to bottom.
Now we have the pattern for the left half, the right half is the same, mirror image. So now we can write down the loop as we know the no of spaces and hashes from top to bottom. In programming we need to understand the underlying principle. Plug in the code afterwards becomes easy.
#include <cs50.h>
#include <stdio.h>
int main(void)
{
int h;
do
{
h = get_int("Pyramid height: ");
}
while (h<1 || h>8);
int n = 8, i, j;
for (i=0; i<h;++i)
{
// left half
for (j=0;j<h-1-i;++j)
printf(" ");
for (j=0;j<i+1;++j)
printf("#");
// two spaces in middle
printf(" ");
// right half, we have omitted the space code as it is not required.
for (j=0;j<i+1;++j)
printf("#");
printf("\n");
}
return 0;
This question already has answers here:
Making a Hash Pyramid
(2 answers)
Closed 6 years ago.
I'm going through the Harvard CS50 online course and one of the problems is to create a "mario style pyramid" using spaces and hashes. I've got the spaces solved but the hashes are giving me trouble. Here's the code:
#include <stdio.h>
#include <cs50.h>
int main(void)
{
//get height between 1 and 23
int height;
do
{
printf("Please enter a height: ");
height = GetInt();
}
while (height < 1 || height > 23);
//build pyramid
for (int i = 0; i < height ; i++)
{
//add spaces
for (int space = height - 1 - i; space >= 0; space--)
printf(" ");
//add hashtags
for (int hash = 2 + i; hash <= height; hash++)
printf("#");
printf("\n");
}
}
When i run it in the terminal with a height of 5 i'm getting this:
####
###
##
#
<-- space here also
when i want this:
##
###
####
#####
######
Any feedback would be appreciated, thanks
Just try it with the following code:
int main(void)
{
int height;
printf("Please enter a height: ");
scanf("%d", &height);
//build pyramid
for (int i = height; i >= 1; i--)
{
//add spaces
for (int space = 1; space < i; space++)
printf(" ");
//add hashtags
for (int hash = height; hash >= i-1; hash--)
printf("#");
printf("\n");
}
}
when the value of height is 5, you get the desired output:
##
###
####
#####
######
See the Working Fiddle.
In your code, when the value of i is 0 in:
for (int i = 0; i < height ; i++)
^^^^^^
the other loops executes as follows:
for (int space = height - 1 - i; space >= 0; space--)
printf(" ");
here, the loop initializes space = 4 (when height is 5) and the loop condition is valid till space >= 0, so it prints the first 4 characters as " ".
And, Finally when it comes to this loop:
for (int hash = 2 + i; hash <= height; hash++)
printf("#");
here, the loop initializes hash = 2 (i was 0 in the first loop, remember that?) and the loop conditions continues till hash <= height. So, it prints the next 4 characters as "#" as the above condition evaluates to 2,3,4,5 in:
(int hash = 2; hash <= 5; hash++)
^^^ ^^^
and the rest of the code carries on and produces the output as:
####
###
##
#
If you are able to understand the above logic, then you'd be able to decode my solution as well :)
I was trying to program a Mario half pyramid in C but my code is not doing anything.
I originally messed up with loop breakers with it putting everything upside down and when I fixed it it is simply asking for an input and not doing anything else.
#include <cs50.h>
#include <stdio.h>
int main(void)
{
int height;
int space;
int rows;
int hashes;
// The code below decides if the users input meets the guide lines
do
{
printf("Enter the heigth of the pyramid here");
height = GetInt();
}
while (height <= 0 || height > 23);
for(rows = 1 ;rows > height ;rows++)
{
// the code gives the number of spaces per row
for(space = height - 1;space >= 1;space--)
{
printf(" ");
};
//The code below gives the number of hashes that have to be printed
for(hashes = height + 1 - space; hashes> 0; hashes--)
{
printf("#");
};
height = height + 1
printf("\n");
}
};
Your for loop is not going to iterate for a single time if height is not less than 1.
for(rows = 1 ;rows > height ;rows++)
{
//....
I modified your code like the following for height = 5
for (rows = 1; rows <= height; rows++) {// iterate up to height times
for (space = height - rows; space >= 1; space--) { // at first print spaces height -1 times. then spaces will be reduced by 1 from previous.
printf(" ");
};
// at first print hashes 2 times. then hashes will be increased by 1 from previous.
for (hashes = rows + 1; hashes > 0; hashes--) {
printf("#");
};
printf("\n");
}
and get output:
##
###
####
#####
######