实验4

//task1_1.c//
#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型数据a，在内存中是连续存放的，每个元素占用4个内存字节单元；

2、char型数据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、数组名a对应的值，和&a[0]是一样，数组名b对应的值，和&b[0]是一样；

 

//task1_2.c//
#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;
    
    printf("sizeof(int) = %d\n",sizeof(int));
    printf("sizeof(char) = %d\n",sizeof(char));
    printf("\n");
    
    //输出二维数组中每个元素的地址、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");
    
    //输出二维数组中每个元素的地址、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; 
    
    
}

 

 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;
}

 

//task.2.c数组实现//
#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 a[13]={0,31,28,31,30,31,30,31,31,30,31,30,31};
    int i,j,s=0;

    for(j=0;j<month;j++)
    {
        s+=a[j];
    }
    s+=day;
    if(month>=3)
    {
        if((year % 4 ==0 )&&(year % 100 != 0)||(year%400==0))
        s+=1;
    
    }
    return s;
}

 

 

 

//task.3//
#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输出课程平均分：%.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;
    double s=0,average;
    for(i=0;i<n;++i)
    {
        s+=x[i];
    }
    average=s/n;
    return average;
}
void sort(int x[],int n)
{
    int i,j,t;
    for(i=0;i<n-1;++i)
     {
        for(j=0;j<n-i-1;++j)
        if(x[j]<x[j+1])
        {
            t=x[j];
            x[j]=x[j+1];
            x[j+1]=t;
        }
    }
}
   
   

 

 

 

//task.4.c//
#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);
    dec2n(x,8);
    dec2n(x,16);
    return 0; 
}
void dec2n(int x,int n)
{
    int i=0,j,a[100];
    char b[100];
    if(n==16)
    {
        for(i=0;x!=0;i++,j++)
        {
            if(x%16==10) b[i]='A';
            else if(x%16==11) b[i]='B';
            else if(x%16==12) b[i]='C';
            else if(x%16==13) b[i]='D';
            else if(x%16==14) b[i]='E';
            else if(x%16==15) b[i]='F';
            else b[i]=x%16+'0';
            x=x/16;
        }
      for(j=i-1;j>=0;j--)
      printf("%c",b[j]);
      printf("\n");
    }
    else 
    {
      do{
        a[i] = x%n;
        x =x/n;
        i++;
        j++;    
        }while(x!=0);
    
    for(j=i-1;j>=0;j--)
      printf("%d",a[j]);
      
    printf("\n");
    }
}

 

 

 

 

 

 

//task.5//
#include<stdio.h>
int main()
{
    
    int n,i,j;
    printf("Enter n:");
    while (scanf("%d",&n)!=EOF)
    {
    int a[n][n];
    for(i=0;i<n;i++)
    {
        for(j=i;j<n;j++)
        {a[i][j]=i+1;}
     } 
    for(j=0;j<n;j++)
    {
        for(i=j;i<n;i++)
        {a[i][j]=j+1;}
    }
    for(i=0;i<n;i++)
    {
        for(j=0;j<n;j++)
        {
            printf("%d  ",a[i][j]);
        }
        printf("\n");
    }
    printf("\n\nEnter n:");
}
    return 0;
}

 

 

 

 

//task.6//
#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]);
}

 

 

//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);
        }
    }
}