제12장 메모리 클래스, 링크와 메모리 관리

//pe12-2a.h
extern void set_mode(int mode);
extern void get_info(void);
extern void show_info();

#include<stdio.h>
int mod = 0;
double fuel_consumed;
double distance;

void set_mode(int mode)
{
	if( mod == -1 )
	  mod = mode;
	  else if( mode < 0 )
	  {
	  	printf("Ibvalid mode specified.mode 0(us) used");
  		mod = 0;
  	 }
	     else if(mode > 1)
	     {
     		printf("Ibvalid mode specified.mode 1(uk) used");
     		 mod = 1;
     	}
	      
	       else
	       mod = mode;
}

void get_info(void)
{
	if(mod == 0)
	{
		printf("Enter distance traveled in kilometers:");
		scanf("%lf",&distance);
		printf("Enter fuel consumed in liters:");
		scanf("%lf",&fuel_consumed);
	}
	else
	{
		printf("Enter distance traveled in miles:");
		scanf("%lf",&distance);
		printf("Enter fuel consumed in gallons:");
		scanf("%lf",&fuel_consumed);
	}
	
}
void show_info()
{
	if(mod == 0)
	{
		printf("Fuel consumption is %.2f liters per 100km
",distance/fuel_consumed); 
	}
	 if(mod == 1)
	  printf("Fuel consumption is %.2f miles per gallon 
",distance/fuel_consumed); 
}

#include<stdio.h>
#include "pe12-2a.h"
int main(void)
{
	int mode;
	
	printf("Enter 0 for metric mode.1 for US mode:");
	scanf("%d",&mode);
	while(mode >= 0)
	{
		set_mode(mode);
		get_info();
		show_info();
		printf("Enter 0 for metric mode.1 for US mode");
		printf("((-1 to quit):");
		scanf("%d",&mode);
	}
	printf("Done
");
	
	return 0;
}

#include<stdio.h>
int count = 0;
int re_count(void);

int main(void)
{
	int cou = 0;
	for(int i = 0; i < 5; i++)
	   cou = re_count();
	printf("the count is %d
",cou); 
}

int re_count(void)
{
	return ++count;
}

#include<stdio.h>
#include<stdlib.h>
#include<time.h>

#define COUNT 100     
int rand_count[COUNT];  //save rand count
void get_count();  //get rand count
void sort(void);  
void display(void);

int main(void)
{
	get_count();
	sort();
	display();
	return 0;
}

void get_count(void)
{
	srand(time(NULL));
	for(int i = 0; i < 100; i++)
		rand_count[i] = rand()%10 + 1;
}

//     
void sort(void)
{
	int temp;
	for(int i = 0; i < COUNT - 1; i++)
		for(int j = 0; j < COUNT -1; j++ )
		{
			if(rand_count[j] < rand_count[j+1])
			{
				temp = rand_count[j+1];
				rand_count[j+1] = rand_count[j];
				rand_count[j] = temp;
			}
		}
}
void display(void)
{
	for(int i = 0; i < COUNT; i++)
    {
        printf("%d ",rand_count[i]);
        if((i+1) % 10 == 0)
	      printf("
");
    }
}

#include<stdio.h>
#include<stdlib.h>
#include<time.h> 
#define COUNT 1000      //1000    
#define NUM 10       //1-10    
int rand_count[NUM];  //        

void get_count();  //get rand count
void display(void); //             

int main(void)
{
	for(int i = 0; i < 10; i++) 
	{
	  get_count();
  	  display();
	}
	return 0;
}

void get_count(void)
{
	for(int j = 0 ; j < NUM; j++)
		rand_count[j] = 0;
	
	srand(time(NULL));
	int temp;
	for(int i = 0; i < 1000; i++)
		{		
		  temp = rand()%10 + 1;
		  rand_count[temp-1]++;
		}
}


void display(void)
{
	printf("1-10        ：
");

	for(int i = 0; i < NUM; i++)
    {
        printf("%d ",rand_count[i]);
        if((i+1) % 10 == 0)
	      printf("
");
    }
}

//pe12-7a.c
#include<stdio.h>
#include<time.h>
#include<stdlib.h>
int number_of_sets  ;//      
int sides  ;//      
int dices ; //      

//           
int rollem(void)
{
	return rand()% sides + 1;
}

//   dices          
int get_one_rolls(void)
{
	int total = 0;
	for(int i = 0; i < dices; i++)
	   total += rollem();
    return total;
} 
void display(int * ptr)
{
	printf("here are %d sets of %d %d-sided dice.
",
              number_of_sets, dices, sides);

	for(int i = 0; i < number_of_sets; i++)
    {
    	printf("%d ",ptr[i]);
    	if((i+1) %10 == 0)
    	 puts("
");
    }
} 
// 
void get_all_rolls(void)
{
	int *pointer;
	pointer = (int *)malloc(number_of_sets * sizeof(int));
	for(int i = 0; i < number_of_sets; i++)
	      pointer[i] = get_one_rolls();
    display(pointer);
    free(pointer);
} 


//pe12-7.h
extern int number_of_sets; //      
extern int sides;//      
extern int dices; //      
extern int rollem(void);
extern void display(int * ptr);
extern void get_all_rolls(void);

//pe12-7b.c
#include<stdio.h>
#include "pe12-7.h"
#include<stdlib.h>
#include <windows.h>  //  GetTickCount()   
int main(void)
{
	//srand((unsigned int)time(0));//      
    srand((unsigned int)GetTickCount());
   printf("Enter the number of sets, 0 to stop.
");
  while (scanf("%d", &number_of_sets) == 1 && number_of_sets > 0)
  {
  	 printf("How many sides and how many dices?
");
     scanf("%d", &sides);
     scanf("%d",&dices);
     get_all_rolls();//
     printf("
Enter the number of sets, 0 to stop.
");
  }
  
  printf("GOOD FORTUNE TO YOU!
");
	
	return 0;
}

#include<stdio.h>
#include<stdlib.h>  // free()     
int * make_array(int elem,int val);
void show_array(const int ar[],int n);
int main(void)
{
	int *pa;
	int size;
	int value;
	
	printf("Enter the number of elements:");
	scanf("%d",&size);
	while(size > 0)
	{
		printf("Enter th initialization vlaue:");
		scanf("%d",&value);
		pa = make_array(size,value);
		if(pa)
		{
			show_array(pa,size);
			free(pa);
		}
		printf("Enter the number of elemnts(<1 to quit):");
		scanf("%d",&size);
	}
	printf("
");
	return 0;
}

int * make_array(int elem,int val)
{
	int *ptr;
	ptr =(int *)malloc(elem * sizeof(int));
	for(int i = 0; i < elem ; i++)
		ptr[i] = val;
	return ptr;
}

void show_array(const int ar[],int n)
{
	for(int i = 0; i < n; i++)
	{
		printf("%d ",ar[i]);
		if((i + 1) % 8 == 0)puts("
");
	}
	puts("
");
}