RLE algorithm

rle.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

static int codes[0xFF]= {0};

static void addcode(unsigned char c)
{
    codes[(int)c]++;
}



char* RLE(const char* str)
{
    if (!str)
        return 0;

    char* data = (char*) malloc(sizeof(char) * 2+1);
    if (!data)
        return 0;

    int i = 0, j = 0;
    int len = strlen(str);
    int rLen = 0;

    for(i=0; i < len; i++)
    {

        data[j++] = str[i];
        for(const char* it = &str[i]; *it == str[i]; it++)
        {
            rLen++;
        }
        i += rLen-1;
        char buff[5] = {0}; // print buffer 
        sprintf(buff, "%d", rLen);
        strcat(&data[j], buff);
        j += strlen(buff);
        rLen = 0;
    }

    return data;
}


int main()
{

    char* d = RLE("aaaaaaaaaaaaaaaaaaasssssssssssssssssssssbbbbbbbbbbbbbbbbbbbbsssssssssssssssssssssasasas");
    printf("%s\r\n", d);
    free(d);

    return 0;
}