实验4

#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.int型数组a，连续存放，每个元素占用4个内存字节单元。

2.char型数组b，连续存放，每个元素占用1个内存字节单元。

3.数组名a对应的值和&a[0]一样,数组名b对应的值和&b[0]一样.

#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、int型二维数组a，在内存中是“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“按行连续存放”的，每个元素占用1个内存字节单元；

 

 

//task2.c switch实现//
#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 s=0;
    switch(month)
    {
        case 12: s+=30;
        case 11: s+=31;
        case 10: s+=30;
        case 9:  s+=31;
        case 8:  s+=31;
        case 7:  s+=30;
        case 6:  s+=31;
        case 5:  s+=30;
        case 4:  s+=31;
        case 3:  s+=28;
        case 2:  s+=31;
        case 1:  s+=day;
    }
    if((year%4==0 && year%100 !=0 || year%400==0)&&month>=3)
    s++;
    return s;
}

 

 

#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");
}
double average(int x[],int n)
{
    int i,sum_=0;
    for(i=0;i<=5;i++)
        sum_=sum_+x[i];
    return sum_/5.0;
}
void sort(int x[],int n)
{
    int i,c,u;
    for(u=0;u<5;u++)

        for(i=1;i<5;i++)
        {
            if(x[i]>x[i-1])
            {
                c=x[i];
                x[i]=x[i-1];
                x[i-1]=c;
            }
        }

}
//计算整型数组x中n个元素均值，并返回
//补足函数average()实现
//×××
//对整型数组x中的n个元素降序排序
//补足函数sort()实现
//×××

 

 

#include <stdio.h>
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);
    dec2n(x, 8);
    dec2n(x, 16);
    return 0;
}

void dec2n(int x, int n)
{
    int i, j;
    int a[20];
    for (i = 0; i < 20; i++)
    {
        if (x / n != 0)
        {
            a[i] = x % n;
            x = x / n;
        }
        else
        {
            a[i] = x;
            break;
        }

    }
    for (j = i; j >= 0; j--)
    {
        if (n == 16 && a[j] >= 10)
        {

            switch (a[j] % 10)
            {
            case 0:printf("A"); break;
            case 1:printf("B"); break;
            case 2:printf("C"); break;
            case 3:printf("D"); break;
            case 4:printf("E"); break;
            case 5:printf("F"); break;
            }

        }

        else
            printf("%d", a[j]);
    }
    printf("\n");
}

 

 

#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");
        }
    }
    return 0;
}

 

 

#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 a[N];
    int i;
    printf("original views:\n");
    printf("views1:hey, c, i hate u.\n");
    printf("views2:hey, c, i love u.\n");
    printf("\n");
    printf("swapping...\n");
    for(i=0;i<N;i++)
    {
        a[i]=views1[i];
        views1[i]=views2[i];
        views2[i]=a[i];
    }
    printf("views1:");
    for(i=0;views1[i]!='\0';i++)
        printf("%c",views1[i]);
        
    printf("\n");
    printf("views2:");
    for(i=0;views2[i]!='\0';i++)
        printf("%c",views2[i]);
        
    printf("\n");    
    return 0;
}

 

 

//task.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);
        }
    }
}