实验4

 task1_1.c

#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;
}

1：int型数组a，在内存中是连续存放的。每个元素占用4个字节。

2：char型数组b，在内存中是连续存放的。每个元素占用1个字节。

3：是；是。

task1_2.c

#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;
}

1：是；4。

2：是；1。

 task2.c

#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 x[12] = { 31,0,31,30,31,30,31,31,30,31,30,31 };
    int leapyear;
    leapyear = year % 4 == 0 && year % 100 != 0 || year % 400 == 0;
    x[1] = 28 + leapyear;
    int s = 0, i;
    for (i = 0; i < month - 1; i++) 
    {
        s = s + x[i];
    }
    return s + day;
}

 

task3.c

#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 j;
    double s = 0.0;
    double result;
    for (j = 0; j < n; j++) 
    {
        s = s + x[j];
    }
    result = s / (n * 1.0);
    return result;
}
void bubble_sort(int x[], int n)
{
    int h, g,t;
    for (g = 0; g < n;g++) {
        for (h=0; h < n; h++)
        {
            if (x[h] < x[h + 1]) {
                t = x[h];
                x[h] = x[h + 1];
                x[h + 1] = t;
            }

        }
    }
}

task4.c

#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) 
{
    int i,j=0;
    char y[16] = { '0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F' };
    char k[16] ;
    while (x != 0) 
    {
        i = x % n;
        x = x / n;
        k[j++] = y[i];
    }
    while (j >= 0)
        printf("%c", k[--j]);
    printf("\n");
}

task5.c

#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] = i+1;
            else
                x[i][j] = j+1;
}

 task6_1.c

 #include <stdio.h>
#include <string.h>
#include <stdlib.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(t, views1);
strcpy(views1, views2);
strcpy(views2, t);
printf("交换后: \n");
printf("views1: %s\n", views1);
printf("views2: %s\n", views2);
system("pause");
return 0;

}

task6_2.c

#include <stdio.h>
#include <string.h>
#include <stdlib.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(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]);
system("pause");
return 0;
}

task7.c

 

#include <stdio.h>
#include <string.h>
#include <stdlib.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]);
    system("pause");
    return 0;
}
void bubble_sort(char str[][M], int n)
{
    
    int t=1;
    while (t==1) {
        int i;
        char x[M];
        for (i = 0; i < N-1; i++)
        {
            if (strcmp(str[i], str[i + 1]) < 0)
                t = 0;
            else
            {
                strcpy(x, str[i]);
                strcpy(str[i], str[i+1]);
                strcpy(str[i+1],x);
                t = 1;
            }
        }
    }


}