实验四

Task1_1

#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\n", b);

    return 0;
}

1.是连续存放的，占四个字节

2.是连续存放的，占一个字节

3.是，是

Task1_2

#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.是，四个

2.是，一个

Task2

#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[12];
    int f = 0, b = 0, c = 0, sum;

    a[0] = 31;a[2] = 31;a[4] = 31;a[6] = 31;a[7] = 31;a[9] = 31;a[11] = 31;
    a[3] = 30;a[5] = 30;a[8] = 30;a[10] = 30;

    if (year % 100 == 0)
    {
        if (year % 400 == 0)
            f = 1;
    }
    else if (year % 100 != 0)
    {
        if (year % 4 == 0)
            f = 1;
    }
    if (f == 1)
        a[1] = 29;
    else if (f == 0)
        a[1] = 28;
    for (b = 0; b < month - 1; b++)
    {
        c += a[b];
    }
    sum = c + day;
    return sum;
}

 

Task3

#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)
{
    int i;
    double sum = 0, ave;
    for (i = 0;i < n;i++)
        sum = sum + x[i];
    ave = sum / n;
    return ave;
}
void sort(int x[], int n)
{
    int i, j, k;
    for (i = 0;i < n - 1;i++)
    {
        for (j = 0;j < n - 1 - i;j++)
        {
            if (x[j] < x[j + 1])
            {
                k = x[j];
                x[j] = x[j + 1];
                x[j + 1] = k;
            }
        }
    }
}

 

Task4

#include <stdio.h>
void dec2n(int x, int n);
int main()
{
    int x;
    printf("请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)
{
    if (n == 2)
    {
        int i;
        int a[80];
        for (i = 0;x != 0;i++)
        {
            a[i] = x % 2;
            x = x / 2;
        }for (i--;i >= 0;i--)
            printf("%d", a[i]);
        printf("\n");
    }
    if (n == 8)
        printf("%o\n", x);
    if (n == 16)
        printf("%x", x);
}

 

 

Task5

#include <stdio.h>
int main()
{
    int n,i,j; 
    while (printf("Enter n:"),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");
   }
    return 0;
}

Task6

#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 a;
char b;
printf("original views:\n%s\n%s\n\n",views1,views2);
for(a=0;views1[a]!='\0';a++)
{
    b=views1[a];
    views1[a] = views2[a];
    views2[a] = b;
}
printf("swapping...\n\n%s\n%s",views1,views2);
return 0;
}

 

Task7

#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;
}
void bubble_sort(char str[][M],int n)
{
    int i,j;
    char c[80];
    for(i=0;i<n-1;i++)
    {
        for(j=0;j<n-i-1;j++)
        {
            if(strcmp(str[j],str[j+1])>0)
            {
            strcpy(c,str[j]);
            strcpy(str[j],str[j+1]);
            strcpy(str[j+1],c);
            }
        }
    }
}