Ceaser program is meant to take your text , add the inputted key to it and display the cyphered text. My code adds 16 to whatever key i input.

I have hardcoded the code to subtract 16 from the key , it fixed all the issues but i have no idea what the real problem is.

CODE

#include <cs50.h>
#include <ctype.h>
#include <math.h>
#include <stdio.h>
#include <string.h>
int main(int argc, string argv[])
{`your text`

if(argc != 2)
{`your text`
    printf("./ceaser (key here)n");
    return 0;
}
else
{
    // Make sure every character in argv[1] is a digit
    int c = argv[1][0];

    if(isdigit(c))
    {
        // Convert argv[1] from a `string` to an `int`
       // int k = argv[1];
        // Prompt user for plaintext
        string p = get_string("Input text to be coded:");
        int j = strlen(p);
        for(int i = 0 ; i < j ; i++)
        {
            //p[i] = p[i] + c;
            printf("%c" , p[i] + (c - 16));

        }

    }
    else
    {
        printf("./ceaser (key here)n");
        return 0;
    }
    }
    }

`