zhui

#include <iostream.h>
#include <cstring>
#define DIG "0123456789ABCDEFGHIGKLMNOPQRSTUVWXYZ"
using namespace std;

int Atoi(char *s, int p){
    int i, a, digit[256] = {0};
    for(i = 0; DIG[i]; i++)
        digit[DIG[i]] = i;
    for(i = a = 0; s[i]; i++)
        a = a * p + digit[s[i]];
    return a;
}

void Itoa(int a, int p, char *s) {
   static int i = 0, n;
   if (a) {
      ++i;
      Itoa(a / p, p, s);
      s[n - i--] = DIG[a % p];
   }
   else
      s[n = i] = '\0';
}

int main(){
   char s[1024] = "29234652";
   Itoa(Atoi(s, 10), 36, s);
   cout << s << endl;
   return 0;
}