【递归】hex2dec

自己捉摸了好久，由于不熟悉。

#include <stdio.h>

int dec2hex(char *p);
int base;
int num;

int main(void)
{
    char *hex = "AD13C";
    int dec;
    dec = dec2hex(hex);

    printf("%d\n", dec);
    return 0;
}

int dec2hex(char *p)
{
    if(*p == '\0')
    {
        base = 1;
        num = 0;
        printf("base = %d\n", base);
    }
    else
    {
        num = dec2hex(p+1);
        if(*p >= '0' && *p <= '9')
            num = num + (*p - '0') * base;
        else if(*p >= 'A' && *p <= 'F')
            num = num + (*p - 'A' + 10) * base;
        base = base * 16;
        printf("base = %d\n", base);
    }
    return num;
}