实验4

task1-1

#include <stdio.h>
#define N 4

int main() {
    int a[N] = {1, 9, 8, 4};          
    char b[N] = {'1', '9', '8', '4'}; 
    int i;

    printf("sizeof(int) = %d\n", sizeof(int));
    printf("sizeof(char) = %d\n", sizeof(char));
    printf("\n");

    // 输出数组a中每个元素的地址、值 
    for (i = 0; i < N; ++i)
        printf("%p: %d\n", &a[i], a[i]);
    printf("\n");

    // 输出数组b中每个元素的地址、值 
    for (i = 0; i < N; ++i)
        printf("%p: %c\n", &b[i], b[i]);
    printf("\n");
    
    // 输出数组名a和b对应的值 
    printf("a = %p\n", a); 
    printf("b = %p\n", b); 

    return 0;
}

①是 4

②是 1

③是 是

#include <stdio.h>
#define N 2
#define M 4

int main() {
    int a[N][M] = {{1, 9, 8, 4}, {2, 0, 2, 2}};
    char b[N][M] = {{'1', '9', '8', '4'}, {'2', '0', '2', '2'}};
    int i, j;

    // 输出二维数组a中每个元素的地址和值 
    for (i = 0; i < N; ++i)
        for (j = 0; j < M; ++j)
            printf("%p: %d\n", &a[i][j], a[i][j]);
    printf("\n");

    // 输出二维数组a中每个元素的地址和值
    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是 4

②是 1

task2

#include <stdio.h>
#define N 13

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

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

    while (scanf_s("%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 a[13] = { 0,31,28,31,30,31,30,31,31,30,31,30,31 };
    int i, days = 0;
    for (i = 1; i < month; i++)
        days = days + a[i];
    days = days + day;
    if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0 && month > 2)
        days = days + 1;
    return days;
}

task3

#include <stdio.h>
#define N 5

// 函数声明 
void input(int x[], int n);
void output(int x[], int n);
double average(int x[], int n);
void bubble_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);
    bubble_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;
}

// 函数定义
// 输入n个整数保存到整型数组x中 
void input(int x[], int n) {
    int i;

    for (i = 0; i < n; ++i)
        scanf_s("%d", &x[i]);
}

// 输出整型数组x中n个元素 
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 = s + x[i];
    ave = s / n;
    return ave;
}

void bubble_sort(int x[], int n)
{
    int i, j, k, m;
    for (i = 0; i < 5; i++)
    {
        m = x[i];
        k = i;
        for (j = i; j < 5; j++)
        {
            if (x[j] > m)
            {
                m = x[j];
                k = j;
            }
        }
        x[k] = x[i];
        x[i] = m;
    }
}

task4

 

#include <stdio.h>
#define N 100
void dec2n(int x, int n); // 函数声明

int main() {
    int x;

    printf("输入一个十进制整数: ");
    while (scanf_s("%d", &x) != EOF) {
        dec2n(x, 2);  // 函数调用: 把x转换成二进制输出
        dec2n(x, 8);  // 函数调用: 把x转换成八进制输出
        dec2n(x, 16); // 函数调用: 把x转换成十六进制输出

        printf("\n输入一个十进制整数: ");
    }

    return 0;
}
void dec2n(int x, int n)
{
    int i;
    int s[N];
    while (n == 2)
    {
       for(i = 0; ; i++)
       {
            s[i] = x % 2;
            x = x / 2;
            if (x <= 0)break;
       }
        int j ;
        for (j = i; j >= 0; j--)
        {
            printf("%d", s[j]);
        }
        printf("\n");
        break;
    }
    while (n == 8)
    {
        for (i = 0; ; i++)
        {
            s[i] = x % 8;
            x = x / 8;
            if (x <= 0)break;
        }
        int j;
        for (j = i; j >= 0; j--)
        {
            printf("%d", s[j]);
        }
        printf("\n");
        break;
    }
    while (n == 16)
    {
        char t[N]={0};
        for (i = 0; ; i++)
        {
            if (x % 16 == 10)t[i] = 'A';
            else if (x % 16 == 11)t[i] = 'B';
            else if (x % 16 == 12)t[i] = 'C';
            else if (x % 16 == 13)t[i] = 'D';
            else if (x % 16 == 14)t[i] = 'E';
            else if (x % 16 == 15)t[i] = 'F';
            else t[i] =(x % 16)+'0';
            x = x / 16;
            if (x <= 0)break;
        }
        int j;
        for (j = i; j >= 0; j--)
        {
            printf("%c", t[j]);
        }
        printf("\n");
        break;
    }
}

task5

#include <stdio.h>
#define N 100

// 函数声明
void func(int x[][N], int n);   // 注意：两维数组作为形参的语法
void output(int x[][N], int n); // 注意：两维数组作为形参的语法

int main() {
    int x[N][N];
    int i, j, n;

    printf("Enter n: ");
    while (scanf_s("%d", &n) != EOF) {
        func(x, n);     // 注意：两维数组作为实参的语法
        output(x, n);   // 注意：两维数组作为实参的语法

        printf("\nEnter n: ");
    }

    return 0;
}

void output(int x[][N], int n) {
    int i, j;

    for (i = 0; i < n; ++i) {
        for (j = 0; j < n; ++j)
            printf("%5d", x[i][j]);

        printf("\n");
    }
}
void func(int x[][N], int n) 
{
    int i,j;
    for (i = 0; i < n; i++)
    {
        for (j = i; j < n; j++)
            x[i][j] = i + 1;
    }
    for (j = 0; j < n; j++)
    {
        for (i = j; i < n; i++)
            x[i][j] = j + 1;
    }
}

task6-1

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <string.h>

#define N 80

int main() {
    char views1[N] = "hey, C, I have not love u yet.";
    char views2[N] = "hey, C, how can I love u?";
    char t[N];

    printf("交换前: \n");
    printf("views1: %s\n", views1);
    printf("views2: %s\n", views2);

    // 交换
    strcpy(t, views1);
    strcpy(views1, views2);
    strcpy(views2, t);

    printf("交换后: \n");
    printf("views1: %s\n", views1);
    printf("views2: %s\n", views2);

    return 0;
}

task6-2

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <string.h>

#define N 80

int main() {
    char views[2][N] = { "hey, C, I have not love u yet.",
                         "hey, C, how can I love u?" };

    char t[N];

    printf("交换前: \n");
    printf("views1: %s\n", views[0]);
    printf("views2: %s\n", views[1]);

    // 交换
    strcpy(t, views[0]);
    strcpy(views[0], views[1]);
    strcpy(views[1], t);

    printf("交换后: \n");
    printf("views1: %s\n", views[0]);
    printf("views2: %s\n", views[1]);

    return 0;
}

 

task7

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <string.h>

#define N 5
#define M 20

void bubble_sort(char str[][M], int n); // 函数声明

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);  // 函数调用 

    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,j;
    char x[M];
    for (i = 0; i < n-1; i++)
    {
        for (j = 0; j < n-1; j++)
        {
            if (strcmp(str[j], str[j + 1]) == 1)
            {
                strcpy(x, str[j]);
                strcpy(str[j], str[j + 1]);
                strcpy(str[j + 1], x);
            }
        }
    }
}