Questions tagged [c]
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566
questions
0
votes
0answers
6 views
Lab 4 not altering output file - using solution word for word
I have looked at all the solutions here on the exchange. I have two issues. Firstly:
const int HEADER_SIZE = 44;
This does not work for me in the context of initializing a header array. I either have ...
0
votes
0answers
12 views
get_string() C function not working
I just began CS50 and was trying to copy some of the examples done on the lecture video. I use opensuse tumbleweed(also a little new to it) and I had installed the cs50 c library just as the ...
0
votes
1answer
20 views
How do I get rid of the "expression result unused" error?
I am trying to get it to where if input "n" and "x" are the same number it will display "years = 0" if not it will run else statement. Instead it was running both the if ...
0
votes
0answers
17 views
PSET1 Credit error mistake
Hope this finds you well. I am having a little bit of trouble with PSET 1s credit problem, the code compiles fine but when running check50 it gives me a few errors.
I tested one of the errors, where ...
0
votes
1answer
13 views
What is the problem with my get_int for the lab 1 question population in C?
when i make the code and i type ./population, the question asked is start size:, and when i type in an x value that is 9 or more, the question keeps reprompting and I keep looking through and I don't ...
0
votes
0answers
13 views
lock_pairs did not correctly lock all non-cyclical pairs
this is my code within the lock_pairs function for the tideman problem in pset3. I've looked through it numerous times and I can't find anything wrong with it.
However, when I run it through check50, ...
0
votes
1answer
23 views
pset4 filter edge corner pixel problem
When I run check50 I am failing for checking the corner pixel as well as 3x3 and 4x4 image.
No matter how long I stare at my code I just can't see the problem.
Any help is greatly appreciated.
...
0
votes
1answer
16 views
Why the pixels are not rendering correctly in recover problem?
I am working on recover problem and suffice to say I am just a beginner. Here is my code:
#include <stdio.h>
#include <stdlib.h>
#include "stdint.h"
#include "stdbool.h"...
0
votes
0answers
16 views
C code wont run. can you help? telephone directory
can you please help me figure out why my code won't run. I do not understand the errors. please help. its suppose to be a working telephone directory
#include<stdio.h>
#include<stdlib.h>
#...
0
votes
1answer
25 views
I have no idea why my speller in pset5 is giving the wrong amount of misspelled words
I am not sure where my mistake is, I keep getting too many misspelled words.
This is the link to check 50 I run on the code:
https://submit.cs50.io/check50/ce552ed87b7d99ac966d9ba7a897bda34bf0a794
// ...
0
votes
1answer
15 views
Plurality exercise - error messages
I am trying to do the Plurality exercise for problem set 3, but when I type this to test it, I get errors even though I believe my program looks correct.
check50 cs50/problems/2021/x/plurality
I get ...
0
votes
0answers
18 views
CS50 PSET3 Tideman Help!
I'm having a little trouble with the add_pairs function because the pairs array refuses to store numbers. I used printf to corroborate the values that were being recorded, and the i and j ints don't ...
0
votes
1answer
14 views
Helping with Valgrind "Conditional jump or move depends on uninitialised value(s)" in simple C code
So right now my code seems to me like it doesnt have issues, it looks like this:
int i;
char hello[] = "Hello World!";
char * str = malloc(strlen(hello)+1);
for(i = 0; i < ...
0
votes
0answers
9 views
pset4 blur, tried this method, I can't figure out what is the problem with my code
It compiles, and passes the check for pixels in the corner, but fails every other test,
before I added the logic for the corners and edges it passed the test for the middle pixels also. I can't ...
0
votes
1answer
27 views
Use of undeclared identifier 'num'
I dont really know where im wrong. it gives me "use of undeclared identifier 'num'" i allready tried to solve it but i have no clue of what is going on
#include <stdio.h>
int maxc = 0,...
0
votes
2answers
18 views
for- loop stop if output A
on pset2/caesar
and only when ciphertext[i] = A or a
for loop stopped ????
0
votes
0answers
13 views
Pset3: Tideman - Sort_pairs
Check50 says that my sort_pairs function is wrong, but with the tests I've used, everything is alright.
Here's the code:
void sort_pairs(void)
{
int biggest_strength_of_victory = preferences[pairs[0]....
0
votes
1answer
23 views
How to convert an unsigned char to a string?
I'm needing to collect byte by byte of an unsigned char and convert it to a string, how can I do that?
I've tried everything but it didn't work.
My example code:
#include <stdio.h>
#include <...
1
vote
1answer
17 views
Mario problem: Program got stuck at user input
// ** Below is the code of mario pset1, its taking input of width multiple times and not executing step after input//
#include <cs50.h>
#include <stdio.h>
#include <math.h>
int main(...
0
votes
0answers
22 views
Why do Escape Sequences in C work differently when I compile code by using GCC?
Why do Escape Sequences in C work differently when I compile code by using GCC? For example,
Input:
#include <stdio.h>
int main(void){
printf("Hello world\n");
}
Output in CS50 ...
0
votes
1answer
21 views
How does the CS50 IDE recognize C functions in advance?
I notice that functions like printf() and toupper() appear in blue without the relevant #include statements in files with names ending in .c. What is happening under the hood to make this happen?
1
vote
1answer
31 views
'stadio.h' file not found
#include <stadio.h>
int main(void) {
printf("hello, world");
}
when i type make hello
clang -ggdb3 -O0 -std=c11 -Wall -Werror -Wextra -Wno-sign-compare -Wno-unused-parameter -Wno-...
1
vote
1answer
34 views
Unable to confirm user input is a number using isdigit in c
My code is attempting to;
take user input from the command line;
check if the input is a whole number;
confirm positively if so;
confirm negatively if not;
however all numbers return a negative ...
0
votes
1answer
12 views
error : function definition not allowed here pls help
i got this error message
pls help
$ make triangle
clang -ggdb3 -O0 -std=c11 -Wall -Werror -Wextra -Wno-sign-compare -Wno-unused-parameter -Wno-unused-variable -Wshadow triangle.c -lcrypt -lcs50 -...
0
votes
1answer
13 views
pset2//caesar : strspn result
I'm struggling to understand :
(argc != 2 || argv[1][strspn(argv[1], "1234567890")])
It works, but I'm trying to understand what's going on inside the if evaluation, and the value argv[1][...
0
votes
1answer
18 views
function output?
I can't get this function to output the desired value of 0.07.
#include <stdio.h>
#include <cs50.h>
#include <math.h>
float i = 1.32;
float quar_val = 0.25;
int func(float val, ...
0
votes
0answers
21 views
CS50 Speller: valgrind test says that bytes are still reachable in 3 blocks
I'm currently at the CS50's pset5, and am working on the "Speller" problem. I managed to do all functions and don't have any compile or runtime errors. When using check50, though, I receive ...
0
votes
1answer
53 views
pset4 filter blur less got stuck
i have been working on blur and it works just fine as i run it. but when i run check50
i get this :
:( blur correctly filters middle pixel
expected "127 140 149\n", not "145 160 169\n&...
0
votes
1answer
37 views
credit pset1 cs50 sum while loop
I was doing the credit problem with the visa test card in the page: 4003600000000014
It passed that test, however in other tests it doesn't pass.
I think it's a matter of the sum that it can't compute ...
0
votes
0answers
11 views
Cannot Compile CS50 Library
I've been running into this problem lately. Here's one of my code:
#include <cs50.h>
#include <stdio.h>
#include <string.h>
// ...
for (int i = 0; i < voter_count; i++)
{
...
0
votes
0answers
9 views
Library = Collection of functions?
do I understand it right, that in that library there are only a collection of functions inside that i can use?
0
votes
1answer
17 views
Why is an Array longer then the input?
why we can access more information than the lenght of the array?
I thought that after the Null (0) the array ends. Why we can access position 40?
1
vote
1answer
44 views
CS50 - PSET 4 - Filter - Edges
//Pixel buffer
RGBTRIPLE pixelBuffer[height][width];
//Iterates on every pixel and calculates Gx and Gy
for (int i = 0; i < height; i++)
{
for (int j = 0; j < width; j++)...
0
votes
0answers
6 views
Error with calculating Egdes in Pset4 Filter (More) Detect Edge problem
// Detect edges
RGBTRIPLE new_pixel(int i, int j, int height, int width, RGBTRIPLE image[height][width])
{
int redx;
int bluex;
int greenx;
int redy;
int bluey;
int greeny;
...
0
votes
1answer
35 views
PSET4 RECOVERY does not recover images correctly
I have started working on PSET 4 RECOVERY. My program compiles successfully, it goes through the first 3 tests no problem, but for the love of me I cannot seem to find the problem.
It just does not ...
0
votes
3answers
19 views
Error retrieving return values from a function
I am currently studying coding in C language and I have doubts about the return of functions, what I am trying to do is the following:
Call the number () function and pass 3 values of the integer ...
0
votes
1answer
25 views
Recover PSET4 Corrupt images
i was working on pset4 recover and my code finds all the image, but everytime it writes to the image the image got corrupted, and i cant find the issue, checked the debugger and it seems going the way ...
0
votes
1answer
25 views
Help to finish my problem - Check50 - Pset4 - Filter Less
I am coding the sepia filter, it is already working, but it does not pass the check50. I think of according to the check50 report, that there is some problem of precision in the calculations, but I ...
0
votes
1answer
60 views
pset4 - (Filter Less ) - Doubts with malloc()
I'm performing the problem set from pset4 to the (filter less) part. I wish to use malloc() to my advantage to speed up image filtering and maybe check50 will accept my solution to the problem.
I ...
1
vote
1answer
50 views
Recover - segmentation fault and other general problems
Hey guys so I've hit a bit of a wall with Recover, when I run my program I get segmentation fault but I also don't know how to end off one jpeg when another header pops up? In essence, I'm not sure ...
1
vote
1answer
65 views
Lecture 5 Linked Lists: What's going on under the hood?
Sheepishly I must admit I am having difficulty understanding how Linked Lists are implemented. Spent an hour and a half just on this part. The following partial code is from the lecture (comments ...
0
votes
1answer
80 views
PSET3 Tideman - What to do with the lock_pairs function?
Can someone please help me with the lock_pairs section of the problem? The lock_pairs function is killing me. I get that you have to compare the pairs to each other and then return false or true in ...
0
votes
1answer
35 views
PSET 1 Credit Card Checksum doesn't add up
I'm having my issues finding the right answer as this is non code related.
The checksum says: "If the total’s last digit is 0, the number is valid!"
This is a credit card number that is ...
0
votes
1answer
24 views
question on Week 1 lecture
I just have a small question. David showed how to compile the source code "Hello.c" file using the make command to make the executable machine code file "Hello" in the lecture. I ...
0
votes
1answer
73 views
Credit (Pset1) - Checksum problem
so I have a problem with the Credit exercise from pset1. I updated my code today after realizing that I didn't split up the digits of the product of the current digit in the card number and 2 and ...
0
votes
1answer
13 views
Command debug not found
when I try to run the command debug
debug ./scores
the message that returns is that :
Command 'debug' not found
0
votes
2answers
46 views
stuck on readability pset2
Hi I am stuck on readability and am not sure what i am doing wrong
$ ./readability
Text: one fish. two fish. red fish. blue fish
8
3
42
13
Grade 13
and my code:
#include <stdio.h>
#include <...
0
votes
1answer
649 views
Lab 8 // Resetting button colors not working properly
I am doing the lab 8 trivia question and I am try to reset all the colors of the buttons when you press another from the rest. I am not sure how to do it. I have the function for resetting the colors ...
0
votes
1answer
25 views
PSet3 Tideman , error with updating ranks array
bool vote(int rank, string name, int ranks[])
{
for (int i = 0; i < candidate_count; i++)
{
if (strcmp(name, candidates[i]) == 0)
{
ranks[rank] = name;
...
0
votes
1answer
23 views
I have included all the libraries, yet it shows errors (pset2)
This is my code:
#include <stdio.h>
#include <cs50.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
int main (int argc, string ...
