实验四

#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连续存放，四个字节

2.char连续存放，一个字节

#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;
}

1.int二维数组连续存放，每个元素4个字节

2.char二维数组连续存放，每个元素1个字节

 

#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("%d%d%d",&year,&month,&day)!=EOF)//按下Ctrl+Z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;
}
int days_of_year(int year,int month,int day)
{int sum=0,i,a[]={0,31,28,31,30,31,30,31,31,30,31,30,31};
if(year % 400 == 0 || year % 100 != 0 && year % 4 == 0)
 {a[2]++;}
for(i=1;i<month;i++)
{
sum+=a[i];
}
sum+=day;
return sum;
}
//函数定义
//补足函数days_of_year的定义
//xxx

 

 

 

 

 

#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)
{ double sum=0;
  int i;
  for(i=0;i<n;i++)
   sum+=x[i];
  return sum/n;
}
void sort(int a[],int n)
{
    int i,j,index;
    int temp;
    int m;
    for(i = 0; i < n-1; i++){
            index=i;
        for(j = i + 1;j < n; j++){ //寻找最小值
            if(a[index]<a[j]) //a[i]若不是最小
                index=j;        //记录最小值下标
        }
         if(index !=i)    //最小值和第i个记录进行互换
        {
            temp=a[i];
            a[i]=a[index];
            a[index]= temp; //a[i]的值赋给被交换的位置
        }
 
    }
}
//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
//××x

#include<stdio.h>
#include<string.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("%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 b[50];
    memset(b,0,sizeof(b));
    int i=0;
    while(x){
        b[i]=x%n;
        if(b[i]>9){
            b[i] += 'A'-10;
        }else{
            b[i] +='0';
        }
        x=x/n;
        i++;
    }
    while(i--){
        printf("%c",b[i]);
    }printf("\n");
}
//待补足

#include <stdio.h>
#define N 100

int main()
{
     int a[N][N] = {0};
     int n;
    int i, j, k;
     printf("Enter n: ");
    while(scanf("%d", &n)!=EOF)
    { 
    for (i = 0; i < n; i++)
     {
         for (j = i; j < n; j++)
         {
            a[i][j] = i + 1;
             a[j][i] = a[i][j];
         }
     }

     for (i = 0; i < n; i++)
     {
         for (j = 0; j < n; j++)
         {
            printf("%2d ", a[i][j]);
         }
         printf("\n");
     }printf("\nEnter 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.";
    int i;
  
 
    printf("original views:\n");
    printf("views1:%s\n", views1);
    printf("views2:%s\n", views2);
 
    printf("\n");
 
    for (i = 0; i < N; i++)
    {
        views1[20] = views1[i];
        views1[i] = views2[i];
        views2[i] = views1[20];
    }
 
    printf("swapping...\n");
 
    printf("views1:%s\n", views1);
    printf("views2:%s\n", views2);
 
    return 0;
}

#include <stdio.h>
#include <string.h>
#define N 5
#define M 20
void bubble_sort(char str[][M], int n); //函数声明
int main()
{
     char name[][M] = {"Bob", "Bi1l", "Joseph", "Tay1or", "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); // 函数调用
     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)
{
     char *tmp;
     int i, j;
    for (i = 0; i < n; i++)
     {
         for (j = 0; j < n - 1 - i; j++)
         {
             if (strcmp(str[j], str[j + 1]) > 0)
             {
                 *tmp = *str[j];
                 *str[j] = *str[j + 1];
                 *str[j + 1] = *tmp;
             }
         }
    }
}