Tag: Convert

This code is a purely fun project and it comes from this challenge at freeCodeCamp. This is just an algorithm challenge which is usually meant for JavaScript, but I decided to do it in C. It will not be used for production reasons . Please leave any comments you find useful, paying particular attention to loops and data types. I purposely used pointer arithmetic, while, and for loops, to explore different approaches to problems. I also left the printf on the number of chips if you want to play with it by uncommenting it. Also note that I have provided 2 examples of binary strings but only one is currently used by default.

#include 
#include 
#include 
#include 
#include 

char* binary_agent(char *bin_str);
char bit_string_decode(char *const str);
bool bit_string_is_valid(char *bit_string);
int main(void)
{
    char str() = "01000001 01110010 01100101 01101110 00100111 01110100 00100000 "
                 "01100010 01101111 01101110 01100110 01101001 01110010 01100101 "
                 "01110011 00100000 01100110 01110101 01101110 00100001 00111111";
    char str2() = "01001001 00100000 01101100 01101111 01110110 01100101 00100000 01000110 01110010 01100101 01100101 01000011 01101111 "
                  "01100100 01100101 01000011 01100001 01101101 01110000 00100001";
    char *result = binary_agent(str);
    printf("%sn", result);
    free(result);
    result = NULL;
    return 0;
}

// Purpose: Return an English translated sentence of the passed binary string
// "Chars" must be space-separated
// E.G. binary_agent("01000001 01110010 01100101");
char* binary_agent(char *bin_str)
{
    assert(bin_str);

    size_t count;
    char *token = NULL;
    char *delim = " ";
    count = 0;
    char *ptr = bin_str;

    while((ptr = strchr(ptr, ' ')) != NULL)
    {
        count++;
        ptr++;
    }

    ptr = NULL;
    //printf("Total number of tokens %lun", count);

    char *output_buffer = malloc(sizeof(char)*(count+1));
    assert(output_buffer);

    token = strtok(bin_str,delim); // token is null-terminated
    if(!token) return NULL;
    output_buffer(0) = bit_string_decode(token);
    size_t i;
    for(i = 1; token != NULL; ++i) //convert to for loop
    {
        token = strtok(NULL, delim);
        if(!token) break;
        output_buffer(i) = bit_string_decode(token);
    }
    return output_buffer;
}

//Parses groups of 8 1s or 0s into a char
char bit_string_decode(char *const str)
{
    assert(str && bit_string_is_valid(str));

    char output = 0;
    size_t i;

    //String needs to be valid for sure here
    for(i = 0; i < 8; ++i)
    {
        switch(str(i))
        {
            case '1':
                output |= 1 << 7-i;
                break;
            case '0':
                break;
        }
    }

    return output;
}
bool bit_string_is_valid(char *bit_string)
{
    assert(bit_string && (strlen(bit_string) == 8));

    while(bit_string && *bit_string != '')
    {
        if((*bit_string != '0') && (*bit_string != '1')) return false;
        bit_string++;
    }
    return true;
}