C PRIMER PLUS（第六版编程练习）12.9编程练习_2题

//pe12-2a.h
#pragma once
void set_mode(void);
void get_info(void);
void show_info(void);
//main()
#include <stdio.h> 
#include "pe12-2a.h" 
int main(void)
{
   
   
	extern int mode;
	printf("Enter 0 for metric mode, 1 for US mode:\n");
	scanf("%d", &mode);
	while (mode &