自己捉摸了好久，由于不熟悉。

#include 
     
      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;}