作业4

1. 实验任务1

#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;
}

#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]);
            printf("\n");
        }
    }
    return 0;
}

2. 实验任务2

#include<stdio.h>
#define N 13
int days_of_year(int year, int month, int day);
int main()
{
    int year, month, day;
    int days;
    while (scanf_s("%d%d%d", &year, &month, &day) != EOF) {
        days = days_of_year(year, month, day);
        printf(" % 4d - % 02d - % 02d是这年的第%d天\n", year, month, day, days);
    }
    return 0;
}
int days_of_year(int year, int month, int day) {
    int isleap=0,i,days=0;
    if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0) {
        isleap = 1;
    }
    int a[13] = { 0,31,28 + isleap,31,30,31,30,31,31,30,31,30,31 };
    for (i = 1; i < month; i++) {
        days += a[i];
    }
    days += day;
    return days;
}

3. 实验任务3

#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 sum=0,ave;
    int i;
    for (i = 0; i < n; ++i) {
        sum += x[i];
    }
    ave = sum / n;
}
void bubble_sort(int x[], int n) {
    int i, j,t;
    for (i = 0; i < n; 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;
            }
        }
    }
    for (i = 0; i < n; ++i) {
        printf("%d ", x[i]);
    }
}

4. 实验任务4

#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);
        printf("\n");
        dec2n(x, 8);
        printf("\n");
        dec2n(x, 16);

        printf("\n输入一个十进制数：");
    }
    return 0;
}
void dec2n(int x, int n) {
    char c[100] = { 0 };
    int i=0,z;
    char y[17] = { '0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F' };
    while (x != 0) {
        z = x % n;
        c[i++] = y[z];
        x = x / n;
    }
    i--;
    while (i >= 0) {
        printf("%c",c[i]);
        i--;
    }
    return;
}

5. 实验任务5

#include<stdio.h>
#define N 100
void func(int x[][N], int n);
void output(int x[][N], int n);
static int x[N][N];
int main()
{
    int i, j, n;
    printf("Enter n:");
    while (scanf_s("%d",&n) != EOF) {
        func(x, n);
        output(x, n);
        printf("\nEnter n:");
    }
    return 0;
}
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] = j+1;
            }
            else {
                x[i][j] = i+1;
            }
        }
    }
}
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");
    }
}

6. 实验任务6

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<string.h>

#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);
    
    strcpy(t, views1);
    strcpy(views1, views2);
    strcpy(views2, t);
    
    printf("交换前”\n");
    printf("views1:%s\n", views1);
    printf("views2:%s\n", views2);
    return 0;
}

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<string.h>

#define N 80
int main()
{
    char views[2][N] = {"hey,c,i have not love u yet.", "hey,c,how can i love u？"};
    printf("交换前”\n");
    printf("views1:%s\n", views[0]);
    printf("views2:%s\n", views[1]);
    char t[N];
    strcpy(t, views[0]);
    strcpy(views[0], views[1]);
    strcpy(views[1], t);
    
    printf("交换前”\n");
    printf("views1:%s\n", views[0]);
    printf("views2:%s\n", views[1]);
    return 0;
}

7. 实验任务7

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

}