实验四

task1_1.c

① int型数组a数组a在内存中是连续存放的，每个元素占用4个内存字节单

② char型数组b数组b在内存中是连续存放的，每个元素占用1个内存字节单元。

③对应的值一样。

#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;
}

task1_2.c

① int型二维数组a，在内存中是否是"按行连续存放"是按行连续存放的，每个元素占用4个内存字节单元。

② char型二维数组b，在内存中是否是"按行连续存放"是的，每个元素占用1个内存字节单元。

#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;}

　　

task2.c

#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_s("%d%d%d", &year, &month, &day) != 0)  // 按下Ctrl+D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;}// 函数定义// 补足函数days_of_year的定义// xx
int days_of_year(int year, int month, int day)
{
    int hh, n, k,h;
    n = 0;
    h = month;
    hh = year % 4 == 0 && year % 100 != 0 || year % 400 == 0;
    int yue[13] = { 0,31,28 + hh,31,30,31,30,31,31,30,31,30,31 };
    for (; month >= 0; month--)
    {
        n += yue[month];
    }
    k = n-yue[h]+day;
    return k;
}

　　

task3.c

#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: ");
    scanf_s("%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// 补足函数实现
void dec2n(int x, int n)
{
    char h[N];
    int i, j = 0, k = 0, l = 0;
    for (i = 0; x != 0; i++, j++)
    {
        k = x % n;
        if (k < 10)
        {
            h[i] = '0' + k;
        }
        if (k >= 10)
        {
            h[i] = 'A' + k - 10;
        }
        x = x / n;
    }
    for (l = j - 1; l >= 0; l--)
    {
        printf("%c", h[l]);
    }
    printf("\n");
}

　　

task4.c

#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: ");
    scanf_s("%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// 补足函数实现
void dec2n(int x, int n)
{
    char h[N];
    int i, j = 0, k = 0, l = 0;
    for (i = 0; x != 0; i++, j++)
    {
        k = x % n;
        if (k < 10)
        {
            h[i] = '0' + k;
        }
        if (k >= 10)
        {
            h[i] = 'A' + k - 10;
        }
        x = x / n;
    }
    for (l = j - 1; l >= 0; l--)
    {
        printf("%c", h[l]);
    }
    printf("\n");
}

　　

task5.c

#include<stdio.h>
int main()
{
    int x[99][99];
    int i, j, k,n;
    while (scanf_s("%d", &n) != EOF)
    {
        for (i = 1; i < n; i++)
            for (j = i - 1; j < n; j++)
                for (k = i - 1; k < n; k++)
                    x[j][k] = i;
        for (j = 0; j < n; j++)
        {
            for (k = 0; k < n; k++)
                printf("%d", x[j][k]);
            printf("\n");
        }
    }
    return 0;
}

　　

task6.c

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

　　

task7.c

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