实验4

实验任务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");
    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;
}

是 4

是 1

一样

#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;
    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;
}

是 4

是 1

实验任务2

#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],i,sum=0;
    for (i = 1; i < 13; i++)
    {
        if (i == 1 || i == 3 || i == 5 || i == 7 || i == 8 || i == 10 || i == 12)
            a[i] = 31;
        else if (i == 2)
        {
            if ((year % 100 != 0 && year % 4 == 0) || (year % 100 == 0 && year % 400 == 0))
            {
                a[i] = 29;
            }
            else
                a[i] = 28;
        }
        else
            a[i] = 30;
    }
        for (i = 1; i < month; i++)
            sum += a[i];
        return sum + day;
}

实验任务3

#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 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;
}
void input(int x[], int n) {
    int i;

    for (i = 0; i < n; ++i)
        scanf_s("%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 sum = 0,i;
    double ave;
    for (i = 0; i<n; ++i)
    {
        sum += x[i];
    }
    ave = 1.0 * sum / n;
    return ave;
}
void bubble_sort(int x[], int n)
{
    int i, j, t;
    for (i = 0; i < n; i++)
    {
        for (j = i; j < n; j++)
        {
            if (x[i] < x[j])
            {
                t = x[i];
                x[i] = x[j];
                x[j] = t;
            }
        }
    }
}

实验任务4

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

int main() {
    int x;

    printf("输入一个十进制整数: ");
    while (scanf_s("%d", &x) != EOF) {
        dec2n(x, 2);
        dec2n(x, 8); 
        dec2n(x, 16);

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

    return 0;
}
void dec2n(int x, int n)
{
    char a[16] = { '0','1','2','3','4','5','6','7','8','9','a','b','c','d','e','f' };
    int b[1000], i, count = 0, j;
    for (i = 0;; i++)
    {
        b[i] = x % n;
        x = x / n;
        if (x == 0)
            break;
        count++;
    }
    for (i = count ; i >=0 ; i--)
    {
        j = b[i];
        printf("%c", a[j]);
    }
    printf("\n");
}

实验任务5

#include <stdio.h>
#define N 100
void func(int x[][N], int n);  
void output(int x[][N], int n); 

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

    printf("Enter n: ");
    while (scanf_s("%d", &n) != EOF) 
    {
        func(x, n); 
        output(x, n);  

        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 = 0; j < n; ++j)
        {
            if (i > j)
                x[i][j] = j+1;
            else
                x[i][j] = i+1;
        }
    }
}

实验任务6

#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);
    strcpy_s(t, views1);
    strcpy_s(views1, views2);
    strcpy_s(views2, t);

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

    return 0;
}

#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]);

    strcpy_s(t, views[0]);
    strcpy_s(views[0], views[1]);
    strcpy_s(views[1], t);

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

    return 0;
}

实验任务7

#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 t[M];
    for (i = 0; i < n; i++) 
    {
        for (j = 0; j < n - 1 - i; j++) 
        {
            if (strcmp(str[j], str[j + 1]) > 0) 
            {
                strcpy_s(t, str[j]);
                strcpy_s(str[j], str[j + 1]);
                strcpy_s(str[j + 1], t);
            }
        }
    }

}