实验4

#include <stdio.h>
#define N 4

int main() {
	int a[N] = {2, 0, 2, 2};
	char b[N] = {'2', '0', '2', '2'};
	int i;
	printf("sizeof(int)=%d\n", sizeof(int));
	printf("sizeof(char)=%d\n", sizeof(char));
	printf("\n");

	for (i = 0; i < N; ++i)
		printf("%p:%d\n", &a[i], a[i]);
	printf("\n");
	for (i = 0; i < N; ++i)
		printf("%p:%c\n", &b[i], b[i]);
	printf("\n");
	printf("a=%p\n", a);
	printf("b=%p\n", b);
	return 0;
}

　　

1.int型数组a是连续存放的，每个元素占用4个字节

2.char型数组是连续存放的，每个元素占用1个字节

3.是，是

 

#include <stdio.h>
#define N 2
#define M 3

int main() {
	int a[N][M] = {{1, 2, 3}, {4, 5, 6}};
	char b[N][M] = {{'1', '2', '3'}, {'4', '5', '6'}};
	int i, j;
	for (i = 0; i < N; ++i)
		for (j = 0; j < M; ++j)
			printf("%p:%d\n", &a[i][j], a[i][j]);
	printf("\n");
	for (i = 0; i < N; ++i)
		for (j = 0; j < M; ++j)
			printf("%p:%c\n", &b[i][j], b[i][j]);
	return 0;
}

　　

1.int型二维数组a是按行连续存放的，一个元素占用4个字节单元

2.char型二维数组b是按行连续存放的，一个元素占用1个字节单元

 

 

 

#include <stdio.h>

int days_of_year(int year, int month, int day);

int main() {
	int year, month, day;
	int days;

	while (scanf("%d%d%d", &year, &month, &day) != EOF) {
		days = days_of_year(year, month, day);
		printf("%4d-%02d-%02d是这一年的第%d天.\n\n", year, month, day, days);
	}

	return 0;

}

int days_of_year(int year, int month, int day) {
	int d = 0, i;
	if ((year % 4 == 0 && year % 100 != 0) || year % 400 == 0) {
		int a[12] = {31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
		for (i = 0; i < month - 1; i++)
			d += a[i];
		d += day;
	} else {
		int a[12] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
		for (i = 0; i < month - 1; i++)
			d += a[i];
		d += day;
	}
	return d;
}

　　

 

 

 

#include <stdio.h>
#define N 5
void input(int x[], int n);
void output(int x[], int n);
double average(int x[], int n);
void sort(int x[], int n);

int main() {
	int scores[N];
	double ave;

	printf("录入%d个分数:\n", N);
	input(scores, N);

	printf("\n输出课程分数: \n");
	output(scores, N);

	printf("\n课程分数处理: 计算均分、排序...\n");
	ave = average(scores, N);
	sort(scores, N);

	printf("\n输出课程均分: %.2f\n", ave);
	printf("\n输出课程分数(高->低):\n");
	output(scores, N);

	return 0;
}

void input(int x[], int n) {
	int i;
	for (i = 0; i < n; ++i)
		scanf("%d", &x[i]);
}

void output(int x[], int n) {
	int i;
	for (i = 0; i < n; ++i)
		printf("%d ", x[i]);

	printf("\n");
}

double average(int x[], int n) {
	int i, s = 0;
	double ave;
	for (i = 0; i < n; ++i)
		s += x[i];
	ave = (double)s / n;

	return ave;
}

void sort(int x[], int n) {
	int i, j, t;
	for (j = 0; j < n - 1; j++)
		for (i = n - 1; i > 0; --i) {
			if (x[i] > x[i - 1]) {
				t = x[i];
				x[i] = x[i - 1];
				x[i - 1] = t;

			}

		}
}

　　

 

 

 

#include <stdio.h>
void dec2n(int x, int n);

int main() {
	int x;

	printf("输入一个十进制整数：");
	scanf("%d", &x);

	dec2n(x, 2);
	dec2n(x, 8);
	dec2n(x, 16);

	return 0;
}

void dec2n(int x, int n) {
	int i;
	int a[25];

	for (i = 0; x > 0; i++) {
		a[i] = x % n;
		x = x / n;
	}

	for (i -= 1; i >= 0; i--) {
		if (n = 16)
			printf("%x", a[i]);
		else
			printf("%d", a[i]);
	}
	printf("\n");
}

　　

 

 

 

#include <stdio.h>
void left(int n);

int main() {
	int n;
	printf("Enter n: ");
	while (scanf("%d", &n) != EOF) {
		printf("\n");
		left(n);
		printf("\nEnter n: ");
	}
	return 0;
}

void left(int n) {
	int a[n][n];
	int i, j, k;
	for (i = 0; i < n; i++) {
		for (j = 0; j < n; j++) {
			k = i > j ? j + 1 : i + 1;
			a[i][j] = k;
		}
	}
	for (i = 0; i < n; i++) {
		for (j = 0; j < n; j++)
			printf("%4d", a[i][j]);
		printf("\n");
	}

}

　　

 

 

 

#include <stdio.h>
#define N 80
#include <string.h>

int main() {
	char views1[N] = "hey, c, i hate u.";
	char views2[N] = "hey, c, i love u.";
	char temp;
	int i = 0;

	printf("original views:\n");
	printf("views1: %s\n", views1);
	printf("views2: %s\n", views2);

	while (views1[i] != '\0') {
		temp = views1[i];
		views1[i] = views2[i];
		views2[i] = temp;
		i++;
	}
	printf("\nswapping...\n");
	printf("views1: %s\n", views1);
	printf("views2: %s\n", views2);

	return 0;
}

　　

 

 

 

#include <stdio.h>
#include <string.h>
#define N 5
#define M 20
void bubble_sort(char str[][M], int n);

int main() {
	char name[][M] = {"Bob", "Bill", "Joseph", "Taylor", "George"};
	int i;
	printf("输出初始名单:\n");
	for (i = 0; i < N; i++)
		printf("%s\n", name[i]);
	printf("\n排序中...\n");
	bubble_sort(name, N);
	printf("\n按字典序输出名单:\n");
	for (i = 0; i < N; i++)
		printf("%s\n", name[i]);
	return 0;
}

void bubble_sort(char str[][M], int n) {
	int i;
	char temp[20];
	for (i = 0; i < n - 1; i++) {
		if (strcmp(str[i], str[i + 1]) > 0) {
			strcpy(temp, str[i]);
			strcpy(str[i], str[i + 1]);
			strcpy(str[i + 1], temp);
		}
	}
}