프로그래밍연습 - 2.[C] 구조체 2, 동적할당, 전처리, 파일 분할

1. 구조체 2

#include <stdio.h>

typedef int INT;
typedef int * PTR_INT;
typedef unsigned int UINT;
typedef unsigned int * PTR_UINT;
typedef unsigned char UCHAR;
typedef unsigned char * PTR_UCHAR;

int main()
{
	INT num1 = 120;
	PTR_INT pnum1 = &num1;
	UINT num2 = 190;
	PTR_UINT pnum2 = &num2;
	UCHAR ch = 'z';
	PTR_UCHAR pch = &ch;
	printf("%d, %u, %c\n", *pnum1, *pnum2, *pch);
}

#include <stdio.h>

struct point
{
	int xpos;
	int ypos;
};

typedef struct point Point;

typedef struct person
{
	char name[20];
	char phoneNum[20];
	int age;
} Person;

int main(){
	Point pos = {10, 20};
	Person man = {"이승기", "010-1211-1111", 11};
	printf("%d %d \n", pos.xpos, pos.ypos);
	printf("%s %s %d \n", man.name, man.phoneNum, man.age);
}

#include <stdio.h>

typedef struct point
{
	int xpos;
	int ypos;
} Point;

void ShowPosition(Point pos)
{
	printf("[%d, %d] \n", pos.xpos, pos.ypos);
}

Point GetCurrentPosition(void)
{
	Point cen;
	printf("Input current pos : ");
	scanf("%d %d", &cen.xpos, &cen.ypos);
	return cen;
}

int main()
{
	Point curPos = GetCurrentPosition();
	ShowPosition(curPos);
	return 0;
}

#include <stdio.h>
// struct   function call by ref

typedef struct point{
	int xpos;
	int ypos;
} Point;

void OrgSymTrans(Point * ptr)
{
	ptr->xpos = (ptr->xpos) *-1;
	ptr->ypos = (ptr->ypos) *-1;
}

void ShowPosition(Point pos)
{
	printf("[%d %d] \n", pos.xpos, pos.ypos);
}

int main()
{
	Point pos = {7, -5};
	OrgSymTrans(&pos);
	ShowPosition(pos);
	OrgSymTrans(&pos);
	ShowPosition(pos);
}

#include <stdio.h>

typedef struct point{
	int xpos;
	int ypos;
}Point;

Point AddPoint(Point pos1, Point pos2)
{
	Point pos = {pos1.xpos + pos2.xpos, pos1.ypos + pos2.ypos};
	return pos;
}

Point MinPoint(Point pos1, Point pos2)
{
	Point pos = {pos1.xpos - pos2.xpos, pos1.ypos -pos2.ypos};
	return pos;
}


int main()
{
	Point pos1= {5, 6};
	Point pos2 = {2, 9};
	Point result; 
	
	result = AddPoint(pos1, pos2);
	printf("[%d, %d] \n", result.xpos, result.ypos);
	result = MinPoint(pos1, pos2);
	printf("[%d, %d] \n", result.xpos, result.ypos);
}

#include <stdio.h>

typedef enum syllabel
{
	Do = 1, Re = 2, Mi = 3, Fa = 4, So = 5, La = 6, Ti =7
} Syllabel;

void Sound(Syllabel sy)
{
	switch(sy)
	{
		case Do:
			puts("도는 하얀 도라지");
			return ;
		case Re:
			puts("레는 둥근 레코드");
			return ;
		case Mi:
			puts("미는 파란 미나리");
			return ;
		case Fa:
			puts("파는 예쁜 파랑새");
			return ;
		case So:
			puts("솔은 작은솔방울");
			return ;
		case La:
			puts("라는 라디오고요");
			return ;
		case Ti:
			puts("시는 졸졸시냇물");
	}
	puts("다함께 부르세~");
}

int main()
{
	Syllabel tone;
	
	for(tone=1; tone <=Ti; tone+=1)
		Sound(tone);
}

 

 

2. 메모리 동적 할당

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

int main()
{
	int *ptr1 = (int *)malloc(sizeof(int));
	int *ptr2 = (int *)malloc(sizeof(int)*7);
	int i;

	*ptr1 = 20;
	for(i=0; i< 7; i++)
		ptr2[i] = i + 1;
	
	printf("%d \n", *ptr1);
	for(i=0; i <7; i++)
		printf("%d ", ptr2[i]);
	
	free(ptr1);
	free(ptr2);
}

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

char * ReadUserName()
{
	char * name = (char *)malloc(sizeof(char) * 30);
	printf("what's your name? ");
	gets(name);
	return name;
}


int main()
{
	char *name1;
	char *name2;
	name1 = ReadUserName();
	printf("name1 : %s \n ", name1);
	name2 = ReadUserName();
	printf("name2 : %s \n\n", name2);
	
	printf("again name1 : %s \n", name1);
	printf("again name2 : %s \n", name2);
	free(name1);
	free(name2);
}

 

 

 

3. 전처리

#include <stdio.h>
#define SQUARE(X) X*X

int main(){
	int num = 20;
	printf("sq of num : %d \n", SQUARE(num));
	printf("sq of -5 : %d \n", SQUARE(-5));
	printf("sq of 2.5 : %g \n", SQUARE(2.5));
}

#include <stdio.h>
#define PI 3.14
#define PRODUCT(X,Y) ((X) * (Y))
#define CIRCLE_AREA(R) (PRODUCT(R, R) * PI)

int main()
{
	double rad = 2.1;
	printf("반지름이 %g인 원의 넓이 : %g \n", rad, CIRCLE_AREA(rad));
}

 

#include <stdio.h>
#define ADD 1
#define MIN 0

int main()
{
	int num1, num2;
	printf("두 개의 정수 입력 :");
	scanf("%d %d", &num1, &num2);
	
#if ADD
	printf("%d + %d = %d \n", num1, num2, num1+num2);
#endif

#if MIN
	printf("%d - %d = %d \n", num1, num2, num1 - num2);
#endif	
}

#include <stdio.h>
//#define ADD 1
#define MIN 0

int main()
{
	int num1, num2;
	printf("두 정수 입력 : ");
	scanf("%d %d", &num1, &num2);
	
#ifdef ADD
	printf("%d + %d = %d \n", num1, num2, num1 + num2);
#endif

#ifdef MIN
	printf("%d - %d = %d \n", num1, num2, num1 - num2);
#endif
}

 

4. 파일 분할

4.1 산술 연산 예제

- main.c

- basicArith.h, basicArith.c

- areaArith.h, areaArith.c

- roundArith.h, roundArith.c

#include <stdio.h>
#include "areaArith.h"
#include "roundArith.h"

int main()
{
	printf("삼각형 넓이 (밑변 10, 높이 5) : %g \n"
			, TriangleArea(10, 5));
	printf("원 넓이 (반지름 : 10) : %g \n"
			, CircleArea(5));
	printf("직사각형 둘레(밑변 2.6, 높이 : 5.5) : %g \n"
			, RectangleRound(2.6, 5.5));
	printf("정사각형 둘레(변 길이 : 7) : %g \n"
			, SquareRound(3));
}

#define PI 3.1415
double Add(double num1, double num2);
double Min(double num1, double num2);
double Mul(double num1, double num2);
double Div(double num1, double num2);

double Add(double num1, double num2)
{
	return num1 + num2;
}

double Min(double num1, double num2)
{
	return num1 - num2;	
}

double Mul(double num1, double num2)
{
	return num1 * num2;
}

double Div(double num1, double num2)
{
	return num1 / num2;
}

double TriangleArea(double base, double height);
double CircleArea(double rad);

#include "basicArith.h"

double TriangleArea(double base, double height)
{
	return Div(Mul(base, height), 2);
}

double CircleArea(double rad)
{
	return Mul(Mul(rad, rad), PI);
}

double RectangleRound(double base, double height);
double SquareRound(double side);

#include "basicArith.h"

double RectangleRound(double base, double height)
{
	return Mul(Add(base, height), 2);
}

double SquareRound(double side)
{
	return Mul(side, 4);
}

4.2 몫, 나머지 연산(조건부 컴파일 이용 - 중복 인클루드 방지)

- main.c

- stdiv2.h

- intdiv4.h

- intdiv4.c

#include <stdio.h>
#include "stdiv2.h"
#include "intdiv4.h"

int main()
{
	Div val = IntDiv(5, 2);
	printf("몫 : %d \n", val.quotient);
	printf("나머지 : %d \n", val.remainder);
}

#ifndef __STDIV2_H__
#define __STDIV2_H__

typedef struct div
{
	int quotient;
	int remainder;
} Div;

#endif

#ifndef __INTDIV4_H__
#define __INTDIV4_H__

#include "stdiv2.h"

Div IntDiv(int num1, int num2);

#endif

#include "stdiv2.h"

Div IntDiv(int num1, int num2)
{
	Div dval;
	dval.quotient = num1/num2;
	dval.remainder= num1%num2;
	return dval;
}