实验4

tesk1-1.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");
    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",b);
    return 0;
}

tesk1-2.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;
    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:%d\n",&b[i][j],b[i][j]);
        }
    }
    return 0;
}

tesk2.c

#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 i;
    int a[13]={0,31,28,31,30,31,30,31,31,30,31,30,31};

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

    return day;
}

tesk3.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 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;
}

void input(int x[],int n)
{
    int i;

    for(i=0;i<n;i++)
        scanf("%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)
{
    double sum;
    int i=0;

    while(i<N)
        sum+=x[i++];

    return sum/n;
}

void sort(int x[],int n)
{
    int i,j,temp;

    for(i=0;i<=n-2;i++)
        for(j=n-1;j>i;j--)
            if(x[j]>x[j-1])
                {
                    temp=x[j];
                    x[j]=x[j-1];
                    x[j-1]=temp;
                }
}

tesk4.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 b[50],i,temp,j;
    char a[18]={'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'};

    for(i=0;x!=0;i++)
    {
        b[i]=x%n;
        x/=n;
    }

    for(i-=1;i>=0;i--)
    {
        temp=b[i];
        printf("%c",a[temp]);
    }

    printf("\n");
}

tesk5.c

#include <stdio.h>

int main()
{
    int n,i,j,temp;

    printf("Enter n: ");
    while(scanf("%d",&n)!=EOF)
    {
        for(i=1;i<=n;i++)
        {
            for(j=1;j<=i;j++)
                printf("%d ",j);

            temp=j-1;

            for(;j<=n;j++)
                printf("%d ",temp);

            printf("\n");
        }
        printf("\nEnter n: ");
    }
    return 0;
}

tesk6.c

#include <stdio.h>
#include <string.h>
#define N 80

int main()
{
    char views1[N]="hey, c, i hate u.";
    char views2[N]="hey, c, i love u.";
    char temp[N];

    printf("original views:\n");
    puts(views1);
    puts(views2);

    printf("\nswappint...\n\n");

    strcpy(temp,views1);
    strcpy(views1,views2);
    strcpy(views2,temp);

    puts(views1);
    puts(views2);
}

tesk7.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按字典序输出名单：\n");
    for(i=0;i<N;i++)
        printf("%s\n",name[i]);

    return 0;
}