Convert base 32 bit decoded string to decimal

Question

I have one string which is base 32 bit decoded now I want to Decode that string I also want to encode any string to base 32 bit decoded string. Is there any way,any Algorithm(even in C) or any API for that so i can solve this issue. Thanx in advance.

Answer 1

I am not sure if I understand your question, but if you want to convert a base 32 number to base 10(decimal) number, take this:

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

#define BASE 32

unsigned int convert_number (const char *s) {
    unsigned int len = strlen(s) - 1;
    unsigned int result = 0;
    char start_ch = 0, ch;
    while(*s != '\0') {
        ch = *s;
        if (ch >= 'a') {
            start_ch = 'a' - 10;
        } else if (ch >= 'A') {
            start_ch = 'A' - 10;
        } else {
            start_ch = '0';
        }

        if(len >= 0)
            result += (ch - start_ch) * pow(BASE, len);
        else
            result += (ch - start_ch);
        ++s;
        --len;
    }

    return result;
}