[누구나 쉽게 즐기는 C 언어 콘서트 - 개정 3판] 13장 Programming 풀이

# 13장 Programming 풀이

 

 

510p_1번)

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

int main()
{
	int num = 0;
	double sum = 0.0;
	double *array;

	printf("요소 개수: ");
	scanf_s("%d", &num);

	array = (double*)malloc(num * sizeof(double));

	for (int i = 0; i < num; i++)
	{
		printf("배열 요소를 입력하시오: ");
		scanf_s("%lf", &array[i]);

		sum += array[i];
	}

	printf("합: %.2lf\n", sum);

	free(array);

	return 0;
}

 

 

 

 

510p_2번)

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

int main()
{
	int num = 0;
	double big = 0.0;
	double* array;

	printf("요소 개수: ");
	scanf_s("%d", &num);

	array = (double*)malloc(sizeof(double) * num);
	for (int i = 0; i < num; i++)
	{
		printf("요소 %d: ", i + 1);
		scanf_s("%lf", &array[i]);
	}
	
	for (int i = 0; i < num - 1; i++)
	{
		if (array[i] < array[i + 1])
		{
			big = array[i + 1];
		}
	}

	printf("최댓값: %.2lf\n", big);

	free(array);

	return 0;
}

 

 

 

 

510p_3번)

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

int main()
{
	int sum = 0;
	int* array;

	array = (int*)malloc(sizeof(int) * 20);

	for (int i = 0; i < 20; i++)
	{
		srand(time(NULL));
		array[i] = rand() % 100;

		sum += array[i];
	}

	printf("수들의 평균: %d\n", sum / 20);

	free(array);
	return 0;
}

 

 

 

 

511p_4번)

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

int main()
{
	int big = 0;
	int* array;

	array = (int*)malloc(sizeof(int) * 20);

	for (int i = 0; i < 20; i++)
	{
		srand(time(NULL));
		array[i] = rand() % 100;
	}

	big = array[0];
	for (int i = 0; i < 19; i++)
	{
		if (array[i] < array[i + 1])
		{
			big = array[i + 1];
		}
	}

	printf("최댓값: %d\n", big);

	free(array);
	return 0;
}

 

 

 

 

511p_5번)

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

int main()
{
	typedef struct rec
	{
		int i;
		float PI;
		char A;
	} my_record;

	my_record* example;

	example = (my_record*)malloc(sizeof(my_record));

	example->i = 10;
	example->PI = 3.14;
	example->A = 'a';

	printf("%d\n", example->i);
	printf("%.2f\n", example->PI);
	printf("%c\n", example->A);

	free(example);
	return 0;
}

 

 

 

 

511p_6번)

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

int main()
{
	struct course
	{
		char subject[30];
		double marks;
	};

	int num = 0;

	printf("구조체 개수: ");
	scanf_s("%d", &num);
	printf("\n");

	struct course* ptr;
	ptr = (struct course*)malloc(sizeof(struct course) * num);

	for (int i = 0; i < num; i++)
	{
		rewind(stdin);
		printf("과목명을 입력하시오: ");
		gets_s(ptr[i].subject, 30);

		printf("성적을 입력하시오: ");
		scanf_s("%lf", &ptr[i].marks);
	}

	printf("\n--------------- 정보 출력 ---------------\n");
	for (int i = 0; i < num; i++)
	{
		printf("%s : %.2lf\n", ptr[i].subject, ptr[i].marks);
	}

	free(ptr);
	return 0;
}