누구나 쉽게 즐기는 C언어 콘서트 9장 실습문제 정답

누구나 쉽게 즐기는 C언어 콘서트 9장 실습문제 정답

 

누구나 쉽게 즐기는 C언어 콘서트 9장 실습문제 정답

 

1번

#include<stdio.h>

void print_array(int *, int);
int get_array_sum(int *, int);

int main(void) {
	int data[10] = { 1, 2, 3, 4, 5, 6, 7, 8, 9 };
	int sum;
	int *a = data;

	sum = get_array_sum(a, 10);
	printf("print_array()\n");

	print_array(a, 10);

	printf("배열 요소의 합 = %d\n", sum);

	return 0;
}

void print_array(int *A, int size) {
	int count;

	for (count = 0; count <= size - 1; count++) printf("%d ", A[count]);
	printf("\n");
}

int get_array_sum(int *A, int size) {
	int count, tmp = 0;

	for (count = 0; count <= size - 1; count++) tmp += A[count];

	return tmp;
}

2번

#include <stdio.h>

void print_reverse(int a[], int n);

int main(void) {
	int arr[5];
	int i;

	printf("5개의 정수를 입력하시오:");
	for (i = 0; i < 5; i++) scanf("%d", &arr[i]);

	print_reverse(arr, 5);

	return 0;
}

void print_reverse(int a[], int n) {
	int *p = a + n - 1;

	printf("역순: ");
	while (p >= a) printf("%d ", *p--);
	printf("\n");
}

3번

#include <stdio.h>
#include <math.h>

void quadratic(int, int, int, double*, double*);

int main(void)
{
	int a = 1, b = 4, c = 3;
	double xplus, xminus;

	quadratic(a, b, c, &xplus, &xminus);

	printf("첫번째 실근: %lf\n", xplus);
	printf("두번째 실근: %lf\n", xminus);

	return 0;
}

void quadratic(int a, int b, int c, double* xplus, double* xminus) {
	*xminus = (-b - sqrt(b*b - 4 * a*c)) / (2 * a);
	*xplus = (-b + sqrt(b*b - 4 * a*c)) / (2 * a);
}

4번

#include <stdio.h>

void get(double, int*, double*);

int main(void) {
	double value = 3.14;
	double f_part;
	int i_part;

	get(value, &i_part, &f_part);

	printf("정수부=%d\n", i_part);
	printf("소수부=%f\n", f_part);

	return 0;
}

void get(double value, int *i_part, double *f_part) {
	*i_part = (int)value;
	*f_part = value - *i_part;
}

5번

#include <stdio.h>
#define WIDTH 10
#define HEIGHT 10

void brighten_image(char *, int);

int main(void) {
	char image[HEIGHT * WIDTH] = {
		0,0,0,0,9,0,0,0,0,0,
		0,0,0,9,9,0,0,0,0,0,
		0,0,9,0,9,0,0,0,0,0,
		0,0,0,0,8,0,0,0,0,0,
		0,0,0,0,9,0,0,0,0,0,
		0,0,0,0,7,0,0,0,0,0,
		0,0,0,0,8,0,0,0,0,0,
		0,0,0,0,9,0,0,0,0,0,
		0,0,0,0,9,0,0,0,0,0,
		0,0,6,6,9,7,7,0,0,0 };

	brighten_image(image, 100);

	return 0;
}
void brighten_image(char *p, int n) {
	int i;

	for (i = 0; i < n; i++)
		if (p[i] < 9)
			p[i]++;
}

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