I can't see what my code for pset2 substitution is missing. When I use check50 to test the program it returns this result:
:) substitution.c exists
:) substitution.c compiles
:( encrypts "A" as "Z" using ZYXWVUTSRQPONMLKJIHGFEDCBA as key expected "ciphertext: Z...", not "ciphertext: Z..."
:( encrypts "a" as "z" using ZYXWVUTSRQPONMLKJIHGFEDCBA as key expected "ciphertext: z...", not "ciphertext: z..."
:( encrypts "ABC" as "NJQ" using NJQSUYBRXMOPFTHZVAWCGILKED as key expected "ciphertext: NJ...", not "ciphertext: NJ..."
:( encrypts "XyZ" as "KeD" using NJQSUYBRXMOPFTHZVAWCGILKED as key expected "ciphertext: Ke...", not "ciphertext: Ke..."
:( encrypts "This is CS50" as "Cbah ah KH50" using YUKFRNLBAVMWZTEOGXHCIPJSQD as key expected "ciphertext: Cb...", not "ciphertext: Cb..."
:( encrypts "This is CS50" as "Cbah ah KH50" using yukfrnlbavmwzteogxhcipjsqd as key expected "ciphertext: Cb...", not "ciphertext: Cb..."
:( encrypts "This is CS50" as "Cbah ah KH50" using YUKFRNLBAVMWZteogxhcipjsqd as key expected "ciphertext: Cb...", not "ciphertext: Cb..."
:( encrypts all alphabetic characters using DWUSXNPQKEGCZFJBTLYROHIAVM as key expected "ciphertext: Rq...", not "ciphertext: Rq..."
:) handles lack of key
:) handles invalid key length
:) handles invalid characters in key
:) handles duplicate characters in key
:) handles multiple duplicate characters in key
However, when I manually type in a key and plaintext it works exactly as it is supposed to. Furthermore, the 'expected' result of check50 seems to be exactly the same as the output so it is not obvious what is wrong.
my code is as follows:
#include <cs50.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
int get_validkey(string A);
int main(int argc, string argv[])
{
if (argc != 2)
{
printf("useage: ./substitution key\n");
return 1;
}
int validation = get_validkey(argv[1]);
if (validation == 1)
{
printf("key must contain 26 alphabetical characters\n");
return 1;
}
// prompting user for plaintext
string plaintext = get_string("plaintext: ");
printf("ciphertext: ");
int length = strlen(plaintext);
for (int c = 0; c <= length ; c++)
{
// printing any non-alphabet characters unchanged
if (plaintext[c] < 'A' || (plaintext[c] > 'Z' && plaintext[c] < 'a') || plaintext[c] > 'z')
{
printf("%c", plaintext[c]);
}
else
{
for (int b = 0; b <= 25; b++)
{
if (plaintext[c] == 65 + b)
{
char upper = argv[1][b];
int up = isupper(upper);
if (up == 0)
{
upper = toupper(upper);
printf("%c", upper);
}
if (up != 0)
{
printf("%c", upper);
}
}
else if (plaintext[c] == 97 + b)
{
char lower = argv[1][b];
int low = islower(lower);
if (low == 0)
{
lower = tolower(lower);
printf("%c", lower);
}
if (low != 0)
{
printf("%c", lower);
}
}
}
}
}
printf("\n");
return 0;
}
// function assesses if the key input is valid and returns 0 if it is and 1 if it is not
int get_validkey(string A)
{
int inputlength = strlen(A);
if (inputlength != 26)
{
return 1;
}
else
{
for (int g = 0; g < 26; g++)
{
// checks if the character is non alphabetical
if (A[g] < 'A' || (A[g] > 'Z' && A[g] < 'a') || A[g] > 'z')
{
return 1;
}
// scans all characters before A[g] to see if it has already been used
for (int k = (g - 1); k >= 0; k--)
{
if (A[k] == A[g])
{
return 1;
}
// also checks if different case of the same character has been used
if (A[k] == A[g] + 32)
{
return 1;
}
if (A[k] == A[g] - 32)
{
return 1;
}
}
// scans all characters after A[g] to check if it has been used already. (Not sure if this is necessary)
for (int l = (g + 1); l < 26; l++)
{
if (A[l] == A[g])
{
return 1;
}
// also checks if a different case of the same letter is used
if (A[l] == A[g] + 32)
{
return 1;
}
if (A[l] == A[g] - 32)
{
return 1;
}
}
}
return 0;
}
}
I am very new to programming and any help would be greatly appreciated.
