C语言中printf直接打出2进制数是%什么?16进制是什么？

#include <iostream>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

using namespace std;





char * get2String(long num)

{

int i = 0;

char * buffer = NULL;

char * temp = NULL;

printf("%d\n", num);





buffer = (char *)malloc(33);

temp = buffer;





for(i=0; i<32; i++)              

{

//temp[i] = num & (1 << (31 - i));

//temp[i] = temp[i] >> (31 - i);//(因为定义为char型所以每个数组成员最大为255如果分步移位会造成第一步移位后数据溢出)

temp[i] =(num&(1<<(31-i)))>>(31-i);

temp[i] = (temp[i] == 0) ? '0' : '1';

}

buffer[32] = '\0';





return buffer;

}

char * get16String(long num)

{

int i = 0;

char * buffer = (char *)malloc(11);

char * temp;





buffer[0] = '0';

buffer[1] = 'x';

buffer[10] = '\0';

temp = buffer+2;





for(i=0; i<8; i++)

{

temp[i] = (char)( (num << (4 * i)) >> 28);

temp[i] = temp[i] >= 0 ? temp[i] : temp[i] + 16;

temp[i] = temp[i] < 10 ? temp[i] + 48 : temp[i] + 55;

}

return buffer;

}





int main()

{

char *p = NULL;

char *q = NULL;

int num = 0;

int a = -9;

printf("%d\n", a>>1);





printf("input num: ");

scanf("%d", &num);





p = get16String(num);

q = get2String(num);







printf("%s\n", p);

printf("%s\n", q);





return 0;

}