Convert base 32 bit decoded string to decimal - iphone

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;
}