实验四

1-1

#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");

    //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是，4

②是，1

③是

1-2

#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;

    //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b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是，4

②是，1

task2

#define _CRT_SECURE_NO_WARNINGS
#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) != 0)//按下Ctrl+D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);
    }
}
    int days_of_year(int year, int month, int day)
    {
        int i, sum = 0;
        int a[13] = { 0,31,28,31,30,31,30,31,31,30,31,30,31 };
        for (i = 1; i < month; ++i)
            sum = sum + a[i];
        sum += day;

        if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0)
            return ++sum;
        else 
            return sum;    

    }

 task3

#define _CRT_SECURE_NO_WARNINGS
#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 = 0.0, ave;
    int i;

    for (i = 0; i < n; ++i)
        sum = sum + x[i];

    ave = sum / n;
    return ave;
}

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;
            }
    int a, b;
    a = x[0];
    x[0] = x[4];
    x[4] = a;
    b = x[1];
    x[1] = x[3];
    x[3] = b;
    
}

task4

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
void dec2n(int x, int n);

int main()
{
    int x;
    printf("输入一个十进制数：");
        scanf("%d", &x);

    dec2n(x, 2);
    dec2n(x, 8);
    dec2n(x, 16);

    return 0;
}

void dec2n(int x, int n)
{
    int s[1000] = { 0 };
    int i, j,sum;
    for (i = 0; x != 0; i++)
    {
        sum = x % n;
        x = x / n;
        s[i] = sum;
    }

    for (j = i - 1; j >= 0; j--)
    {
        if (s[j] >= 10)
            printf("%c", s[j] + 55);
        else
            printf("%d", s[j]);
    }
    printf("\n");
}

task5

 

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#define N 100
void fun(int x[N][N], int n);
void output(int x[N][N], int n);
int main()
{
    int x[N][N], n;
    while (printf("Enter n:"), scanf("%d", &n) != 0)
    {
        fun(x, n);
        output(x, n);
    }
    return 0;
}
void fun(int x[N][N], int n)
{
    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < n; ++j) {
            if (i - j >= 0)
                x[i][j] = j + 1;
            else
                x[i][j] = x[i][j - 1];
        }
    }
}
void output(int x[N][N], int n)
{
    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < n; ++j) {
            printf("%d  ", x[i][j]);
        }
        printf("\n");
    }
}

task6

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

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

    printf("views1:%s\n", views1);
    printf("views2:%s\n", views2);

    char t[N];
    int i;
    for (i = 0; i < N; ++i)
    {
        t[i] = views1[i];
        views1[i] = views2[i];
        views2[i] = t[i];
    }

    printf("swapping....\n");
    printf("views1:%s\n", views1);
    printf("views2:%s\n", views2);


    return 0;
}

task7

#define _CRT_SECURE_NO_WARNINGS
#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, k;
    char t[M];
    for (i = 0; i < N - 1; i++)
    {
        for (j = 0; j < N - 1 - i; j++)
        {
            k = strcmp(str[j], str[j + 1]);
            if (k > 0)
            {
                strcpy(t, str[j]);
                strcpy(str[j], str[j + 1]);
                strcpy(str[j + 1], t);
            }
        }
    }
    
}

收获：字符串函数的使用