When I run check50 i get this:

:) caesar.c exists.
:) caesar.c compiles.
:) encrypts "a" as "b" using 1 as key
:( encrypts "barfoo" as "yxocll" using 23 as key
output not valid ASCII text
:) encrypts "BARFOO" as "EDUIRR" using 3 as key
:) encrypts "BaRFoo" as "FeVJss" using 4 as key
:( encrypts "barfoo" as "onesbb" using 65 as key
output not valid ASCII text
:( encrypts "world, say hello!" as "iadxp, emk tqxxa!" using 12 as key
output not valid ASCII text
:) handles lack of argv[1]
:) handles non-numeric key
:) handles too many arguments

I am not sure what it is meant by "not valid ASCII text" or what the error is. When I run the question which I got "wrong" , I get the correct output in the terminal, but check50 marks it as wrong.

#include <stdlib.h>
#include <ctype.h>
#include <stdio.h>
#include <cs50.h>
#include <string.h>
#include <math.h>

int main(int argc, string argv[])
{
    if (argc != 2)
    {
        return 1;
    }
    
    string bob=argv[1];
    
    int lower_letters[]={'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z'};
    int upper_letters[]={'A', 'B', 'C', 'D', 'E','F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'};
    
    for (int e=0; e<strlen(bob); e  )
    {
        for (int g=0; g<26; g  )
        {
            if ((bob[e])==(lower_letters[g]))
            {
                printf("do not enter something that is not a number \n");
                return 1;
            }
        }
    }
    

    int total = atoi(argv[1]);
    
    if (total<0)
    {
        printf("do not input something that is a negative value\n");
        return 1;
    }

    
    string word1 =get_string("plaintext: ");
    printf("ciphertext: ");

    
    for (int i =0; i<strlen(word1); i  )
    {
        if ((word1[i]==' ') || (word1[i]==',') || (word1[i]=='.') || (word1[i]=='!'))
            {
                printf("%c",word1[i]);
            }
        
        for (int a =0; a<26; a  )
        {
            if ((word1[i]==lower_letters[a]) && (a total>26))
            {
                printf("%c",lower_letters[(a total)-26]);
            }
            
            if (word1[i]==lower_letters[a])
            {
                printf("%c",lower_letters[a total]);
            }
            
            
            if ((word1[i]==upper_letters[a]) && (a total>26))
            {
                printf("%c",upper_letters[(a total)-26]);
            }
            
            if (word1[i]==upper_letters[a])
            {
                printf("%c",upper_letters[a total]);
            }
            
        }
        
    }
    printf("\n");
}

Can I please have help getting rid of the error "not valid ASCII text" please?

CodePudding user response：

           if ((word1[i]==lower_letters[a]) && (a total>26))
           {
               printf("%c",lower_letters[(a total)-26]);
           }
           
           if (word1[i]==lower_letters[a])
           {
               printf("%c",lower_letters[a total]);
           }

Though you account for values of a total greater than 26, you erroneously allow the second if body, which doesn't account for this, to execute for those values, too. Also the subtraction -26 is inappropriate for values 52 or higher.

You can replace the above code with

            if (word1[i]==lower_letters[a])
                putchar(lower_letters[(a total)%26]);

- of course the same applies to upper_letters.