Questions tagged [array]
The array tag has no usage guidance.
116 questions
0
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1
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CS50 Pset 2 Substitution - Array size errors
I'm using a for loop to assign chars to each element of an array one at a time. The array has been assigned a size and the for loop runs the same number of iterations as the array size, but I find ...
- 3
3
votes
2
answers
58
views
Why can you say the name of an array is a pointer to the first element of the array in C?
I have tried to understand why you can say the name of an array is a pointer to its first element in C. Could you please tell me if my understanding below is correct?
Both the name of an array and the ...
- 69
-1
votes
1
answer
47
views
Pset 4 Filter (More) -- PLZ HELP
When I declare the array earlier, I end up with the wrong output. But when I declare it inside the loop, the final output is correct.
Plz tell me how to explain this.
The wrong one:
void edges(int ...
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0
votes
1
answer
41
views
pset1 credit 2023 , do while loop with arrays/intervals
#include <cs50.h>
#include <stdio.h>
int main(void)
{
long n;
do
{
n = get_long("13 digits or at max 15, 16 card number: ");
}
while(n < ...
- 27
0
votes
1
answer
21
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Argument list in c
what is an argument list in c? Please I need a very simple explanation that if possible I'll remember for life! also... show me one containing an array
0
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1
answer
4k
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How to find if element is not in an array
Does anyone know of an easy way in C to check if a an element is NOT in a given array?
I think it would be fairly easy to determine if an element IS in an array by looping through it and seeing if an ...
1
vote
0
answers
1k
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pset2 - Bulbs - reversing array turns out wrong
I managed to make the right sequence of binary code (in reverse).
Next, I do a for loop for reversing it, but it prints out wrong. I have no idea what happens, as the original array is correct, ...
- 11
0
votes
2
answers
270
views
pset2 bulbs - getting array out of while loop
I'm working on the pset2 Bulbs problem and I've come to a place where I don't know what to do next. This code takes user text input and converts it to ascii; I can see that the array is being filled ...
- 1
0
votes
1
answer
106
views
Converting an array to lowercase
I am trying to convert an array to lowercase, and store the values as a new array.
#include <cs50.h>
#include <stdio.h>
#include <ctype.h>
int main(int argc, string argv[])
{
...
- 1
0
votes
1
answer
829
views
comparison between pointer and integer ('const char' and 'char')
I'm not familiar with C, not sure what this error means.. could anyone help?
#include <ctype.h>
#include <cs50.h>
#include <stdio.h>
#include <string.h>
// Points assigned to ...
- 101
0
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1
answer
203
views
Undeclared Identifier error in array
In the code below (photo), I am trying to index into the two different arrays, one with capital letters and one with lowercase letters. When I make this program, I keep getting the following error ...
0
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1
answer
69
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How to get accurate float average of numbers
I'm in Lecture 2 on Arrays, and I am playing with the example Professor Malan gave about taking a user's input for the number of test scores, as well as for the scores themselves, and outputting the ...
0
votes
1
answer
24
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substitution question segmentation fault issue
I am doing the substitution question and I keep running into this segmentation fault issue but i do not understand what exactly is causing the memory access issue. once j=4, the memory fails to be ...
0
votes
1
answer
478
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
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1
answer
28
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?
0
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3
answers
34
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
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1
answer
66
views
Help with Either Command Line Argument or Arrays for Problem set 2 Caesar
I am on Problem Set 2: Caesar. Right now I'm trying to write code that first checks if the second command line argument is a int and if it does prints the integer. I got my program to compile after ...
- 17
0
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1
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40
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When I'm creating array
This has me confused.
In the following code, I create an array of characters initialized at size 7. The array needs to store at least 6 characters, so I've made it large enough to do that (I think?). ...
0
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2
answers
1k
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Caesar : Extra random characters at the end of a char ciphertext array
I'm having a problem with an output. Sometimes output adds an extra characters, different each time the code runs. For example, when I use key "1" and write "a", it displays "...
0
votes
1
answer
90
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Having Trouble using StrCpy with Command Line argument for Problem Set 2 Caesar. Trouble with Array
Hello I'm still fairly raw at this coding thing so i'm sure im making rookie mistakes. I'm doing Problem Set 2 caesar and I've hit a wall and haven't been able to move forward. What I have been trying ...
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0
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1
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17
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How can i arrange the output in decending order In this program? [closed]
#include <stdio.h>
int main()
{
int n,i;
printf("Enter a number: ");
scanf("%d",&n);
for (i=0; i<=n; ++i)
{
if (i%(7*13*19)==0)
{
...
- 3
0
votes
1
answer
26
views
PSet 5 Speller - Expected Identifier
Been stuck on Speller for 2 days and could really please use some help.
My initial idea is just to create an array of linked lists with 26 buckets (N = 26) and very simply hash the words by only the ...
- 3
0
votes
1
answer
75
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
1
answer
1k
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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 &...
- 1
0
votes
1
answer
40
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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 ...
1
vote
1
answer
294
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?
- 13
0
votes
1
answer
30
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 &...
- 31
0
votes
1
answer
103
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 ...
- 17
0
votes
1
answer
59
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
1
answer
307
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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 ...
- 15
0
votes
1
answer
56
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
1
answer
43
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
1
answer
32
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 = ...
- 33
0
votes
2
answers
141
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 ...
- 3
0
votes
1
answer
62
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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 ...
- 13
0
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1
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79
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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 ...
- 21
0
votes
1
answer
135
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
1
answer
698
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 ...
- 312
0
votes
1
answer
147
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 ...
- 1
0
votes
1
answer
27
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
1
answer
132
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 ...
- 19
0
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1
answer
421
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 ...
- 36
0
votes
1
answer
768
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 ...
- 15
0
votes
1
answer
37
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?
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0
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1
answer
91
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* ...
- 103
0
votes
1
answer
4k
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
1
answer
37
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'...
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0
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1
answer
58
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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] ...
- 9
0
votes
3
answers
203
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("%...
- 9
0
votes
1
answer
28
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 ...
- 179