作业 4

#include <stdio.h>
#define N 4

int main() {
    int a[N] = { 1, 9, 8, 4 };
    char b[N] = { '1', '9', '8', '4' };
    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;
}
//数组a存放连续，每个占4个字节
//数组b存放连续，每个占一个字节
//一样

#include <stdio.h>
#define N 2
#define M 4

int main() {
    int a[N][M] = { {1, 9, 8, 4}, {2, 0, 2, 2} };
    char b[N][M] = { {'1', '9', '8', '4'}, {'2', '0', '2', '2'} };
    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;
}
//二维数组a是按行连续存放的，每个占4字节
//二维数组b是按行连续存放的，每个占1个字节

#include <stdio.h>
#define N 13

int days_of_year(int year, int month, int day);

int main() {
    int year, month, day;
    int sum;

    while (scanf_s("%d%d%d", &year, &month, &day) != EOF) {
        sum = days_of_year(year, month, day);
    }

    return 0;
}

int days_of_year(int year, int month, int day)
{
    int sum=0;
    switch (month)
    {
    case 1:sum = 0; break;
    case 2:sum = 31; break;
    case 3:sum = 59; break;
    case 4:sum = 90; break;
    case 5:sum = 120; break;
    case 6:sum = 151; break;
    case 7:sum = 181; break;
    case 8:sum = 212; break;
    case 9:sum = 243; break;
    case 10:sum = 273; break;
    case 11:sum = 304; break;
    case 12:sum = 334; break;
    default:printf("wrong "); break;
    }
    sum = sum+day;
    if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0&&month>2)
        sum += 1;
    else
        sum = sum ;
    printf("%4d-%2d-%0d是这一年的第%d天.\n\n", year, month, day, sum);
    return 0;
}

#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 bubble_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);
    bubble_sort(scores, N);

    printf("\n输出课程的均分：%.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_s("%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 s=0, a;
    int i;
    for (i = 0; i < n; i++) {
        s += x[i];
    }
    a = s * 1.0 / N;
    return a;
}
void bubble_sort(int x[], int n) {
    int i, j, m;
    for (m = 0; m < n; m++) {
        for (i = 0; i < n; i++) {
            if (x[i] > x[i + 1]) continue;
            else
            {
                j = x[i];
                x[i] = x[i + 1];
                x[i + 1] = j;
            }
        }
    }
}

#include<stdio.h>
#define N 100
void dec2n(int x, int n);
int main() {
    int x;
    printf("输入一个十进制数：");
    while (scanf_s("%d", &x) != EOF) {
        dec2n(x, 2);
        dec2n(x, 8);
        dec2n(x, 16);
        printf("\n输入一个十进制数：");

    }
    return 0;

}
void dec2n(int x, int n) {
    char dic[16] = { '0','1','2','3','4','5','6','7','8','9','A','B','C','D','F' };
    char ans[N];
    int t, s, i = 0;
    do {

        t = x % n;
        ans[i++] = dic[t];
        x = x / n;

    } while (x > 0);
    ans[i] = x;
    for (i; i >= 0; i--) {
        printf("%c", ans[i]);

    }
    printf("\n");
}

#include <stdio.h>
#define N 100


void func(int x[][N], int n);   
void output(int x[][N], int n); 

int main() {
    int x[N][N];
    int i=0, j=0, n;

    printf("Enter n: ");
    while (scanf_s("%d", &n) != EOF) {
        func(x, n);     
        output(x, n);   
        printf("\nEnter n: ");
    }

    return 0;
}
void output(int x[][N], int n) {
    int i, j;

    for (i = 0; i < n; ++i) {
        for (j = 0; j < n; ++j)
            printf("%5d", x[i][j]);

        printf("\n");
    }
}

void func(int x[][N], int n)
{
    int i, j;
    for (i = 0; i < n; i++) {
        for (j = 0; j < n; j++)
        {
            if (i < j)
                x[i][j] = i + 1;
            if (i >= j)
                x[i][j] = j + 1;
        }
    }

}

#include <stdio.h>
#include <string.h>
#pragma warning(disable:4996)
#define N 80


int main() {
    char views1[N] = "hey, C, I have not love u yet.";
    char views2[N] = "hey, C, how can I love u?";
    char t[N];

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

    // 交换
    strcpy(t, views1);
    strcpy(views1, views2);
    strcpy(views2, t);

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

    return 0;
}

#include <stdio.h>
#include <string.h>
#pragma warning(disable:4996)
#define N 80

int main() {
    char views[2][N] = { "hey, C, I have not love u yet.",
                         "hey, C, how can I love u?" };

    char t[N];

    printf("交换前: \n");
    printf("views1: %s\n", views[0]);
    printf("views2: %s\n", views[1]);

    // 交换
    strcpy(t, views[0]);
    strcpy(views[0], views[1]);
    strcpy(views[1], t);

    printf("交换后: \n");
    printf("views1: %s\n", views[0]);
    printf("views2: %s\n", views[1]);

    return 0;
}

#include <stdio.h>
#include <string.h>
#pragma warning(disable:4996)
#define N 5
#define M 20

void bubble_sort(char str[][M], int n); // 函数声明

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);  // 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)
{
    int i, j;
    char x[100];
    for (j = 0; j < N - 1; j++)
        for (i = 0; i < N - j - 1; i++)
            if (strcmp(str[i], str[i + 1]) > 0)
            {
                strcpy(x, str[i]);
                strcpy(str[i], str[i + 1]);
                strcpy(str[i + 1], x);
            }
}