Questions tagged [array]
The array tag has no usage guidance.
95
questions
0
votes
1answer
14 views
Getting different outputs when I use debug50 and when I run the program
When I use debug50 on this program I get 26 as the value of 'a' but when I run it I get random large values of 'a'.
#include <cs50.h>
#include <stdio.h>
#include <string.h>
#include &...
0
votes
1answer
14 views
cs50 array initializer must be an initializer list
i have started coding in c but i keep getting errors i don,t know how to solve
maybe it is because i am used to coding in php language but i hope anybody can help me
#include <stdio.h>
#include &...
0
votes
1answer
25 views
Having trouble identifying non-decimal digit in Caesar PSET 2
I'm working on Caesar from Problem Set 2. I have done the first step to check for a single command line argument, but I'm stuck on how to check the argument to see if any characters are non - decimal ...
0
votes
1answer
14 views
Week 2 passing array example problem?
Hi, I have problem understanding the concept of 'passing an array by reference instead of value' and I cant understand this example. Can anyone explain to me why does it take 10, 22 as final answer?
0
votes
1answer
15 views
When I multiply my array by 2 it doesn't give expected value
Also, please when I try to add "firstnumsum", it doesn't give expected value and I don't know what to do.
#include <cs50.h>
#include <stdio.h>
#include <string.h>
#include &...
0
votes
1answer
34 views
Readability compiling issue
Readability (Problem Set 2)
#include <stdio.h>
#include <cs50.h>
#include <string.h>
#include <ctype.h>
#include <math.h>
// Letters detects letters
// Words detects ...
0
votes
0answers
49 views
Encrypt plaintext in substution.c
Here is my encryption of plaintext after validation the key.
//Encrypt Code
string plaintext = get_string("plaintext: ");
// int array[26] = {0};
string encText = plaintext;
//converts user ...
0
votes
1answer
52 views
My code for Caesar gets segmentation error when executed, but in debugger it works fine
I'm getting a segmentation error as soon as I execute this program. I've run it through the debugger and it works fine and outputs the correct ciphertext. There's gotta be something going on in the ...
0
votes
1answer
217 views
check50 claiming pairs are sorted incorrectly
On Problem Set 3, check50 has flagged my program as not having sorted the pairs correctly. However, the pairs array appears to be sorted in every case I've tried. I used insertion sort and had ...
0
votes
1answer
39 views
Why is this generating wrong output and Runtime - out of bound error?
I have a program below, which gets some random numbers from users and then multiply every second to the last digit by 2, stores it into an array and print out the value of each array index.
It seems ...
0
votes
1answer
29 views
In pset2, Vigenere, I made and used an array that I would like for it to be explained
I’ve successfully solved Caesar and Vigenere pset but made and used an array that I stumbled upon through trial and error but don’t exactly know why and how it worked. I’m hoping someone could clarify ...
0
votes
1answer
26 views
PSet2 why isn't this providing output
This segment of code only prints out blank lines. Key is the correct integer, but I must be handling the array of characters incorrectly. Thoughts?
int key = atoi(argv[1]);
for (int i = 0, c = ...
0
votes
2answers
123 views
Pset3 Resize Array not storing data properly
I'm not sure where the issue is here, but from the looks of debug I only store anything in my horizontal array (line) once despite seeing the debugger hitting that section of code properly. I assume I ...
0
votes
1answer
54 views
Pset2 Vigenere, array with garbage
I am getting some garbage values when declaring my array. I kinda understand that when declaring without initializing it provides garbage values, but I don't understand why the array is larger than ...
0
votes
1answer
64 views
Caesar not getting output
I'm stuck troubleshooting what is wrong with my code. It prompts for plaintext correctly, but when entered returns a blank "ciphertext: ".
# include <stdio.h>
# include <cs50.h>
# include ...
0
votes
1answer
19 views
Why string variable has no square bracket?
Though it's said that string is an array of characters why string variable does not have square brackets on the immediate right?
In CS50 we call string as
string s
why not as string[]?
then how can ...
1
vote
1answer
146 views
array size in C
I have question regarding array size declaration in C. I see that if I declare an array in the main function without specifying its size like
int arr[];
arr[0] = 7;
arr[1]= 8;
it shows an error ...
0
votes
1answer
42 views
How to get maximum element of array from index a to index b?
I keep getting the error
format specifies type 'int' but the argument has type 'int ()(int , int, int)'.
printf("%d", get_max);
I'm new to pointers and coding C in general and still haven't ...
0
votes
1answer
23 views
Why am I able to insert an element into a hash tree via Main() but not via a function call?
I'm fairly certain this has something to do with pointers and the function using copies instead, but I'm not sure how...because I've inserted the pointer as a parameter for create();
#include <...
1
vote
1answer
117 views
Pset2: Copying string contents
I just can't seem to get this right.
The example in the week 2 short Arrays is as follows:
int foo[5]{1,2,3,4,5};
int bar[5]
for(j=0;j<5;j++)
{
bar[j]=foo[j];
}
This does not seem to work with ...
0
votes
1answer
211 views
CS50 PSET2 code will not compile
I would appreciate any help that could be given with my code below (+ error codes below that):
My code will not compile and the primary error apparently is an "undeclared identifier" refering to ...
0
votes
1answer
155 views
Problem accessing the last element of the array
I've decided to implement the load function using trie, which I've defined as
typdef struct trie
{
struct trie letters[27];
bool isWord;
}trie;
then later, when I try to ...
0
votes
1answer
33 views
Pset4 - Array declaration- Heap
In shorts of Pset4 it was mentioned, that pointers are created in heap. Does it mean, that all arrays are stored in heap?
0
votes
1answer
86 views
Pset5 Dictionary C Struct Array Call In Load Function Issue
I've defined the struct as following:
// Node struct
typedef struct node
{
// Node value
char word[LENGTH + 1];
// Node Pointer to next value/node
struct node* ...
0
votes
1answer
1k views
I'm getting a runtime error on an array and I'm not sure why:
The following code Compiled but gave me an error (credit.c:21:7: runtime error: index 15 out of bounds for type 'int [15]') on the last line included while running:
int m;
int r;
int counter;
int ...
1
vote
1answer
34 views
Passing SQL values into arrays
I'm designing a budgeting website for the final project. One of the features that I want to implement is to be able to track how much money you've spent for each item category.
The SQL command that I'...
0
votes
1answer
57 views
pset vigenere skipped over if statement
for (int i = 0, j = strlen(s), k = 0; i < j; i++, k++)
{
if (isalpha(s[i]))
{
if (isupper(s[i]))
{
if (argv[1][k] ...
0
votes
3answers
200 views
pset2 vigenere shifting characters by the same
for (int i = 0, j = strlen(s), k = 0; i < j; i++, k++)
{
if (isalpha(s[i]))
{
if (isupper(s[i]))
{
if (argv[1][k] != '\0')
{
printf("%...
0
votes
1answer
25 views
pset7: why do we need [0] in from of list? (e.g. someData[0]['dic']?)
Just completed pset7, gosh it was a long one, took a month!
Am curious as to why we need to have a [0] in front of the list to get the "pure" data?
For instance, when we get back a list while ...
0
votes
2answers
2k views
pset2 caesar converting from ascii to alphabetical
#include <stdio.h>
#include <cs50.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
int main(int argc, string argv[])
{
if (argc == 2)
{
int ...
0
votes
1answer
54 views
Declaring an array of structure pointers
How to declare an array of structure pointers? I need to create a collection of linked list. Is it same as declaring ordinary arrays? If
0
votes
1answer
110 views
Array declaration need explicit size?
Can I create an array with no specific size or intializer? I'm trying to make an array of 26 english character but I don't want to just declare 26 slots right from the beginning
int main(void)
{
...
1
vote
1answer
426 views
Pset4 Resize.c Array Overstepping
I have been stuck on resize for a while. I am currently struggling on the vertical portion of resize. I am using the "rewrite" method as explained in the problem spec. My program does resize an image ...
0
votes
1answer
1k views
Pset4 - Recover (usage of sprintf)
When I am working on Pset4 - Recover, I realize I do not understand the concept of array and pointer. Although I finally worked it out, I would be very grateful if you guys can explain the following:
...
0
votes
1answer
50 views
Game of Fifteen - Move Function - getting wrong coordinates?
I have been working on the game of fifteen problem and seem to be having an issue. I keep getting an "Illegal Move" when it is a legal move. I think I have found part of the issue and I would just ...
0
votes
1answer
880 views
Why this code leads to segmentation fault?
1) In CS50 ide, it does not even compile giving error: format specifies type
'int *' but the argument has type 'int' [-Werror,-Wformat]
scanf (" %d", array[n]);
2) In codeblocks, it runs ...
0
votes
1answer
58 views
handlign multidimesional arrays as function arguments and return values
So I stuck at the pset3, at the place where you need to implement game of fifteen. How can I pass multidimensional array as an function argument? And how can I return multdimesional array as a ...
0
votes
1answer
160 views
How could you create a dynamic array of strings in C?[Beginner]
How do you create a dynamic array of strings? Like if I had this code
printf("What are the names of your pets?");
what piece of code would I write to get multiple string answers from the user?
(I'm ...
0
votes
1answer
656 views
trail of strange characters after printing character array
I wrote my vigenere cipher program and everything works fine, but when I run check50 I get the following error:(p is the plaintext string)
char c[strlen(p)];
for(int i = 0, j = 0, l = strlen(p), n = ...
0
votes
1answer
183 views
How to use fseek along side arrays? Pset4 recover
I'm re-wrote this code and did not get any output or error. Tried valgrind and nothing was leaked.
I suspect it's either:
1) my fseek is not moving my cursor in inpt 'card.raw'
2) and/or.. because ...
0
votes
2answers
93 views
Pset 2 - Vigenere Checking Command Line Input
I am working on the Vigenere portion of the pset and appear to have it totally working, yet when I ran the checker I realized that I had not created a test for non-alphabet characters in the command ...
0
votes
2answers
3k views
Split a sentence ito an array of words without using strtok
I need to split a sentence contained in a char pointer into an array of words. I've tried several methods (as I cannot use strtok. The following method I used extracts the different words, but it ...
0
votes
1answer
43 views
pset3 move: won't move tiles in the same row
So I have reviewed similar questions on here but can't quit fix my move code. It will correctly move tiles from within one column to row below (say 3 in the initial position for a 3x3 board). But it ...
0
votes
2answers
6k views
Subscripted value is not an array
I am using exactly the same code as at HowStuffWorks to create a bubbling sorting. But I cannot compile code as I get the following error message:
sorting.c:29:22: error: subscripted value is not an ...
2
votes
2answers
119 views
how effective would it have been to use an array for the dictionary?
I just completed pset5 using a trie, but I'm curious about other methods.
How effective would it have been to load the dictionary into an array and then use a binary search function to locate words ...
0
votes
1answer
35 views
Taking an array as input from User and Displaying the same back
I'm trying to take a list of numbers from user as input and store it in an array. Later I'll be displaying this array using a printf function.
I'm trying to take this input in 2 ways: as user prompt ...
0
votes
1answer
42 views
2D array of given size
I want to create a 2D array of ints, where the array's dimension is given at run time (not compile time). So far, I have been using:
int **ptr = malloc(m * sizeof(int*));
for (size_t i = 0; i < m;...
0
votes
1answer
429 views
Difference between Pass by Value and Pass by Reference (a practical example)
at the end of Doug's video on arrays he explains how variables get passed in function calls in comparison to how arrays work.
void set_array(int array[4]);
void set_int(int x);
int main (void)
{
...
1
vote
2answers
583 views
declaring char array vs malloc
I was watching the week 5 lecture and David said that a chunk of memory can be allocated two ways:
using malloc();
declaring an array of a certain size (char buffer[10]).
Is there really any ...
0
votes
1answer
87 views
How do you specify a section/segment of an array?
I am working on the binary search project in pset 3. I want to specify that if the sought value is greater than the middle value of the sorted array, that the function should then only look in the ...
