实验4

Task 1.1

#define _CRT_SECURE_NO_WARNINGS
#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.不连续存放；4个。

2.连续存放；1个。

3.一样；一样。

Task 1.2

#define _CRT_SECURE_NO_WARNINGS
#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. 是；4个。

2.是；1个。

Task 2

#define _CRT_SECURE_NO_WARNINGS
#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 ans = 0, i;
    int a[13] = { 0,31,28,31,30,31,30,31,31,30,31,30,31 };
    if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0)
    {
        a[2] = 29;
        for (i = 0; i < month; i++)
        {
            ans += a[i];
        }
        ans += day;
    }
    else
    {
        for (i = 0; i < month; i++)
        {
            ans += a[i];
        }
        ans += day;
    }
    return ans;
}

Task 3

#define _CRT_SECURE_NO_WARNINGS
#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)
{
    double sum = 0, ans;
    for (int i = 0; i < n; i++)
    {
        sum += x[i];
    }
    ans = sum / n;
    return(ans);
}

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

Task 4

#define _CRT_SECURE_NO_WARNINGS
#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);
    printf("\n");
    dec2n(x, 8);
    printf("\n");
    dec2n(x, 16);
    return 0;
}

void dec2n(int x, int n)
{
    int digit, x1;
    digit = x % n;
    x1 = x / n;
    if (x == 0)
    {
        ;
    }
    else
    {
        dec2n(x1, n);
        if (n >= 10)
        {
            if(digit>=10)
            {
                printf("%c", (char)((digit - 10) + 'A'));
            }
            else
            {
                printf("%d", digit);
            }
        }
        else
        {
            printf("%d", digit);
        }
    }
}

Task 5

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
int main()
{
    int i, j, k, n;
    printf("Enter n: ");
    while (scanf("%d", &n) != EOF)
    {
        for (i = 1; i <= n; i++)
        {
            for (j = 1; j <= n; j++)
            {
                k = i > j ? j : i;
                printf("%3d", k);
            }
            printf("\n");
        }
        printf("Enter n: ");
    }
    return 0;
}

Task 6

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#define N 80
int main()
{
    char views1[N] = "hey, c, i hate u.";
    char views2[N] = "hey, c, i love u.";
    char step;
    int i = 0;
    printf("oringinal views:\n");
    printf("views1: %s\n", views1);
    printf("views2: %s\n", views2);
    while (views1[i] != '\0')
    {
        step = views1[i];
        views1[i] = views2[i];
        views2[i] = step;
        i++;
    }
    printf("\nswapping...\n\n");
    printf("views1: %s\n", views1);
    printf("views2: %s\n", views2);
    return 0;
}

Task 7

#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);
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, j;
    char a[M];
    for (i = 0; i < N; i++)
    {
        for (j = 0; j < N - 1; j++)
        {
            if (strcmp(str[j], str[j + 1]) > 0)
            {
                strcpy(a, str[j]);
                strcpy(str[j], str[j + 1]);
                strcpy(str[j + 1], a);
            }
        }
    }
}