Questions tagged [vigenere]

Vigenere Cipher, one of the assignments in Problem Set 2. It's like Caesar Cipher, but with a twist.

Filter by
Sorted by
Tagged with
3
votes
1answer
474 views

Pset2 Vigenere 'szz' instead of 'rby'

I fail one test case, and just the one portion of it. Expecting the following on standard out — xoqmd, rby gflkp!\n ... but received the following on standard out instead — xoqmd, szz gflkp! rby =\...
2
votes
1answer
347 views

Why does my vigenere not pass check50 although it gives the correct output?

When checking vigenere.c with check50, I get the following :) vigenere.c exists :) vigenere.c compiles :( encrypts "a" as "a" using "a" as keyword \ expected output, but not "a" :( encrypts "world,...
2
votes
1answer
3k views

pset2 vigenere error “incompatible integer to pointer conversion”

This is the error I get: vigenere.c:34:34: error: incompatible integer to pointer conversion passing 'char' to parameter of type 'const char *'; take the address with & [-Werror,-Wint-...
2
votes
1answer
246 views

Expression result unused in Vigenere

I am getting this error: expression result unused and I don't know what that means. I use the code it's pointing to (green underline), just like I do in my Caesar cipher which works: The other posts ...
2
votes
1answer
622 views

Failing one test case with check50 on pset2 - encrypts “say” to “szz” instead of “rby”

encrypts "world, say hello!" as "xoqmd, rby gflkp!" using "baz" as keyword # Checks 0 Running... clang -o vigenere vigenere.c -lcs50 -lm. ✔ 1 Expecting an exit code of 0. ✔ 2 Running... ...
2
votes
1answer
134 views

Don't understand Vigenere cipher?

I don't understand why we could attack Vigenere cipher when we know the key's length? Can anyone give me a hint? Thank you very much?
1
vote
2answers
766 views

pset2 (vigenere) - Check50 error problems

I'm stuck on an issue with my code. After completing my code and making sure it works as should, I run check50 and this is what I get; jharvard@appliance (~/Dropbox/pset2): check50 2014/x/pset2/...
1
vote
1answer
60 views

vigenere sometimes prints extra characters at the end of ciphertext in an unpredictable pattern

Check50 yields 2 error messages (the rest is correct): :( encrypts "a" as "a" using "a" as keyword output not valid ASCII text :( encrypts "world!$?" as "xoqmd!$?" using "baz" as keyword output not ...
1
vote
4answers
156 views

Cs50's vigerene encrypting problem

My code complies well but encrypts the text in the wrong way.Could someone help me find the problem? any help will be appreciated here is my code: #include <stdio.h> #include <cs50.h> #...
1
vote
1answer
3k views

Vigenere cipher coding drama!

your help is appreciated and please feel free to critique my coding approach. My concern is, not only that the code isn't working, but that I maybe complicating this more than it needs to be. Working ...
1
vote
4answers
772 views

Vigenere Cipher Doesn't Work Properly

I have been trying for way too long to make my Vigenere cipher work, but now I am so confused I don't even know what I am doing. I need some guidance in what it is that I am doing wrong. When I ran ...
1
vote
1answer
462 views

cs50/pset2/vigenere: Code works but check50 rejects 2 item

check50 message: https://cs50.me/checks/c053757544cd74cafb77554759754b8ee4ee37a8 The code doesn't encrypts "a" as "a" using "a" as keyword. It adds a wierd character in the end and I don't know why. ...
1
vote
2answers
129 views

vigenere.c key just wraps around … if there is space in plain text it seems to ignore that key and move on to next

int main(int argc, string argv[]) { string k; k = argv[1]; if(argc == 2) { for(int i=0,j=strlen(k); i<j; i++) { if( isdigit(k[i])) { ...
1
vote
1answer
139 views

Vigenere -Isalpha only checking first char of key

When checking the command line argument in Vigenere.c to see if it contains any non-alphabetic characters, I can't get my for loop to iterate past the first character. I have read all of the posts on ...
1
vote
1answer
96 views

Pset2- Vigenere: returning error on BaRFoo only

I am trying to complete vigenere's cipher by the end of tonight before I am shortly without internet. I have been working on this one error for several hours and cannot figure out how to fix it. The ...
1
vote
1answer
103 views

vigenere output “incompatible pointer types”

I'm trying to solve pset2 vigenere, but I'm having some troubles. I'm using two functions to adapt the key to the text and then to apply the cipher. When I run the last function, I can't get any ...
1
vote
1answer
111 views

Pset2 - Vigenere fails check50 with “expected exit code 0, not 1”

I'm at my wits' end. My code for vigenere compiles fine using make vigenere within CS50 IDE. However, when I run check50, I get this: :) vigenere.c exists. :( vigenere.c compiles. expected exit ...
1
vote
1answer
450 views

why am i getting “can't check until a frown turns upside down”?

as shown why am i getting this.Please just give me a clue or prompt something.I'll fix it by myself.
1
vote
2answers
103 views

CS50 PSET2 VIGENERE problem with key lenght in loop

I have a problem printing the word "world". My code is the following (EDIT): #include <cs50.h> #include <ctype.h> #include <stdio.h> #include <stdlib.h> #include <string.h&...
1
vote
2answers
105 views

Finished vigenere, but it fails to work as it should

*UPDATE: Actually, I can't understand a thing now. Let's take an example from check50. Our program should encrypt "world, say hello!" with a keyword "baz". It expects "xoqmd, rby gflkp!" as a correct ...
1
vote
2answers
165 views

CS50 vigenere.c works for lower but not upper case letters

The following is my code, I'm not sure where I went wrong with my code, but when I run it, it seems to work for lower case letters but not uppercase. This isn't the full code, due to academic honesty, ...
1
vote
1answer
153 views

Can't get the 'z' using % 26 on my Vigenère Cypher

I've been trying for a while to get this right but I guess I can't do the math. I'm using this line to encrypt each character for the Vigenères Cypher: int letter = ((p(i) - 96) + (k[j] - 97) % 26 + ...
1
vote
2answers
58 views

PSET 2 Vigenere - only getting symbols as output

So far in Vigenere i've gotten to the point with a single character key, and when I tried to test it, everything works except my output is entirely ����. Here is my code for the shift function and ...
1
vote
1answer
194 views

Key looping in Vigenere

I've reached the final step of Vigenere, but I don't really understand how do I loop the key over plaintext. This is the shift function I've created: int shift(char c) { if(isalpha(c)) { ...
1
vote
1answer
47 views

Pset2 - Vigenere - Encypts all variations of “barfoo” as “ca\…” (no case issues)

This is my first question on Stack Exchange. I had a few different issues with this problem but I felt I'd finally sorted them out until I ran into this. I've been working for a number of hours today ...
1
vote
1answer
131 views

Help with understanding the wrap-around method for Vigenere Pset

I'm having troubles with implementing the wrap around method needed for passing this problem. As you will see, my code so far encypher a number of plaintext letters as equal as the number of the "key" ...
1
vote
2answers
89 views

pset2 vigenere problems

I am kind of stuck with my Vigenere Code so far... and i really feel like don´t know how to work it out from here! Any kind of advice is much appreciated, or i might be stuck here forever :( #include ...
1
vote
1answer
134 views

CS50 Vigenere expected output, not a prompt for input

when I check my program, there is the "expected output, not a prompt for input" error for every input they are trying to check. however, when I am testing it, all inputs seem to be exactly the same as ...
1
vote
1answer
60 views

I get “/opt/sandbox50/bin/run.sh: line 31: 304…” when I try to include j— in my loop

#include <stdio.h> #include <cs50.h> #include <stdlib.h> #include <ctype.h> #include <string.h> int main (int argc, string argv[]) { //checks if argc is 2 if (...
1
vote
1answer
85 views

Sometimes the vigenere cipher went wrong but i can't figure out why~please help!

it compile like this: ~/workspace/pset2/ $ check50 2015.fall.pset2.vigenere vigenere.c :) vigenere.c exists :) vigenere.c compiles :) encrypts "a" as "a" using "a" as keyword :( encrypts "world, ...
1
vote
1answer
92 views

Vigenere corect encryption with weird letters at the end

so here is my Vigenere code do //Key validation { if (argc != 2) { printf("You must enter key!"); return 1; } else { for (int i = 0; i < strlen(argv[...
1
vote
1answer
446 views

Vigenere key counts spaces in progression

Whenever I type plaintext into my vigenere cipher, it moves forward one letter when it encounters spaces or punctuation, even though the key does not affect those characters. How can I prevent this? ...
1
vote
2answers
1k views

pset2 , vigenere. ASCII math struggle

something weird is going on with my code. I get the first word ("Meet" with key "bacon") right, but after that, things are getting really hairy. here is my code. I would really apreciate any help, I'...
1
vote
1answer
296 views

PSET2 Vigenere segmentation fault

I am getting nuts trying to figure out why my vigenere application gives a "Segmentation fault (core dumped)" every time I try to run it (my code is there). Can someone point out some mistakes that ...
1
vote
1answer
137 views

pset 2, Vigenere: How do I stop the keyword from looping if there is a “nonalpha” in the sentence?

My problem is that while the program loops through the sentence to be encrypted, my keyword (i.e.) bacon, doesn't stop looping when there is i.e. a space in the sentence. So instead of Sentence: ...
1
vote
1answer
121 views

Having problem in checking keyword of vigenere when it has &, (, or )

If the keyword includes &, (, or ), the program does not yell at the user for re-input, instead, comes back with the following messages for various inputs. Please note v6 is a vigenere trial ...
1
vote
1answer
694 views

pset2 vigenere doesn't work check50 with BaRFoo

I finished my vigenere and it works good with all the parameters but when I go through check50 with BaZ keyword, check50 give this answer jharvard@appliance (~/Dropbox/CS50/pset2): ./vigenere BaZ ...
1
vote
1answer
281 views

Trouble verifying the keyword in vigenere

I'm having trouble verifying the argv[1] keyword along the guidelines of the assignment. I've tried to implement an if ... else statement the checks if argc is 2 and argv[1] is alpha, if so, run ...
1
vote
1answer
482 views

Pset2 Vigenere. Works for lower and uppercase letters separately, but not for whole code

I've worked on (and dreamed about) Vigenere for a few days now, and I'm almost there. I think! If I try out my code separately for lower and uppercase letters (by commenting out the irrelevant part), ...
1
vote
1answer
290 views

pset2 vigenere; isalpha is accepting numbers in argv[1]

I'm using the construct if(isalpha(argv[1][i]) == 0) to determine if the chars are alphabetical in argv[1] with a for loop. The program compiles, however, isalpha is not working. If I enter, for ...
1
vote
1answer
72 views

Vigenere almost working, but fails somewhere

I give up, I can't make it work. Please kindly point me to a line where I make mistake. // input validation if (argc != 2) { printf("Invalid argument. Please, try again\n"); return 1; } ...
1
vote
1answer
116 views

Vigenere print error

I've got my code to cycle through the plaintext index p and the key index. However I keep getting an error when I am printing and can't figure it out. When I use the test spec using bacon as the key ...
1
vote
0answers
75 views

Vigenere - Incorrect output

I have made a mistake in the equation for the new output. char newmsg = (((plain[i] - 97 + key[j % klength]) % 26) + 97); Can someone please give me a clue as to what I did wrong here? ...
1
vote
1answer
733 views

Vigenere fails check50 test “encrypts ”BaRFoo“ as ”CaQGon“ using ”BaZ“ as keyword”

I successfully completed the Vigenere program and I was recently testing it with Check50. My problem is that there is only one test that fails, and I don't know why: :( encrypts "BaRFoo" as "CaQGon" ...
0
votes
2answers
15k views

How to Wrap Around Array Indexes?

I have the Vigenere encryption portion working properly, but can't seem to figure out how to wrap around argv[1] indexes. My first for loop declared two ints, i and j, and incremented each int with ...
0
votes
1answer
2k views

How to Handle “rejects ”Hax0r2“ as keyword” in Vigenere?

So I made my Vigenere program and it passes all the tests except for the last one about not accepting keys with non-alphas. Now, I have a check in my program to stop this, and when it detects a non-...
0
votes
1answer
1k views

Incompatible pointer types error vignere

Can anyone explain this error? Here is my code: int main(int argc, string argv[]) { // code snipped int c = strlen(argv); // code snipped Here is the error: vig.c:15:20: error: incompatible ...
0
votes
1answer
249 views

extra characters in Vigenere pset2 2016

I am working on the Vigenere pset and seem to be getting the correct encryption but the output has nonsense characters added to it. For example: :( encrypts "a" as "a" using "a" as keyword \ ...
0
votes
1answer
516 views

PSET 2 - Vigenere: How do I wrap around my key to the plaintext?

Having some trouble with pset2 vigenere. Here is my code: #include <stdio.h> #include <cs50.h> #include <string.h> #include <ctype.h> int main(int argc, string argv[]) { ...
0
votes
2answers
78 views

Pset 2 Vigenere Increment Problem

My Code: int main(int argc,string argv[]) { // Checks if the program got an agrument if (argc != 2) { printf("Pls dn't spuk teh prgoram"); return 1; } else { ...

1
2 3 4 5
10