实验4 数组

//task1_1
#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");

    // 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，占用4个;
② 是，占用1个;
③ 是，是.*/

//task1_2
#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;

    // 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，占用4个;
② 是，占用1个.*/

//task2
#include <stdio.h> 
int days_of_year(int year, int month, int day); // 函数声明 

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

    while (scanf("%d%d%d", &year, &month, &day) != EOF) // 按下Ctrl+Z终止 
    {
        days = days_of_year(year, month, day); // 函数调用 
        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, 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;

    if (((year % 4 == 0 && year % 100 != 0) || year % 400 == 0) && month > 2)
        d += 1;

    return d;
}

//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 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;
}

// 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("%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");
}

// 计算整型数组x中n个元素均值，并返回 
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;
}

// 对整型数组x中的n个元素降序排序 
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;
            }
        }
}

//task4

#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); // 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

    return 0;
}

// 函数定义 
// 功能: 把十进制数x转换成n进制，打印输出
void dec2n(int x, int n)
{
    char a[50];
    int i = 0, j;
    while (x != 0)
    {
        if (x % n >= 10)
            a[i] = x % n + 55;
        else
            a[i] = x % n + 48;
        x = x / n;
        i++;
    }

    for (j = i - 1; j >= 0; j--)
        printf("%c", a[j]);

    printf("\n");
}

//task5

#include<stdio.h>
#define N 50
#define M 50

int main()
{
    int n, i, j, x[N][M];
    printf("Enter n: ");
    while (scanf("%d", &n) != EOF)
    {
        for (i = 0; i <= n - 1; i++)
        {
            for (j = 0; j <= n - 1; j++)
            {
                if (i <= j)
                    x[i][j] = i + 1;
                else
                    x[i][j] = j + 1;
                printf("%4d", x[i][j]);
            }
            printf("\n");
        }
        printf("\nEnter n: ");
    }
    return 0;
}

//task6

#include <stdio.h>
#define N 80

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

    int i, j;
    char t;

    printf("original views:\n");

    printf("views1:");
    for (i = 0; i < N; i++)
        printf("%c", views1[i]);
    printf("\nviews2:");
    for (j = 0; j < N; j++)
        printf("%c", views2[j]);
    printf("\n");

    printf("\nswapping...\n\n");

    for (i = 0; i < N; i++)
        for (j = 0; j < N; j++)
            if (i == j)
            {
                t = views1[i];
                views1[i] = views2[j];
                views2[j] = t;
            }
    printf("views1:");
    for (i = 0; i < N; i++)
        printf("%c", views1[i]);
    printf("\nviews2:");
    for (j = 0; j < N; j++)
        printf("%c", views2[j]);
    printf("\n");

    return 0;
}

//task7

#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 t;
    char temp[M];
    for (t = 0; t < N - 1; t++)
        for (n = 0; n < N; n++)
            if (strcmp(str[n], str[n + 1]) > 0)
            {
                strcpy(temp, str[n]);
                strcpy(str[n], str[n + 1]);
                strcpy(str[n + 1], temp);

            }
}