4

一

#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");
// 输出一维int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");
// 输出一维char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;
}

 

 

#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

#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("%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 sum = 0;
    int i;
    
    int a[N]={0,31,29,31,30,31,30,31,31,30,31,30,31};
    if(year%4==0&&year%100!=0||year%4==0)
    a[2]=29;
    else
    a[2]=28;
    
    for(i=0;i<month;i++)
    sum+=a[i];
    return sum+day;
}

 

 三

#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("%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 average = 0.0;
    int i;
    for(i=0;i<n;++i){
        average+=x[i];
    }
    average=average/n;
    return average;
    
}

void bubble_sort(int x[], int n){
    int i,j,t;
    for(i=0;i<n-1;++i){
        for(j=n-2;j>=0;--j){
            if(x[j]<x[j+1])
            {
                t=x[j];
                x[j]=x[j+1];
                x[j+1]=t;
            }
        }
    }
}

 

 四

#include <stdio.h>
#define N 100
void dec2n(int x, int n); 

int main() {
    int x;

    printf("输入一个十进制整数: ");
    while(scanf("%d", &x) != EOF) {
        dec2n(x, 2);  
        dec2n(x, 8);  
        dec2n(x, 16); 

        printf("\n输入一个十进制整数: ");
    }

    return 0;
}

void dec2n(int x, int n){
    char a[N]={'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'};
    char b[N];
    int count=0;
    while(x!=0){
    b[count++]=a[x%n];
    x=x/n;    
    }
    int i;
    for(i=count-1;i>=0;--i)
    printf("%c",b[i]);
    printf("\n");
}

 

 五

#include <stdio.h>
#define N 100

// 函数声明
void func(int x[][N], int n); // 注意：两维数组作为形参的语法
void output(int x[][N], int n); // 注意：两维数组作为形参的语法

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

printf("Enter n: ");
while(scanf("%d", &n) != EOF) {
func(x, n); // 注意：两维数组作为实参的语法
output(x, n); // 注意：两维数组作为实参的语法

printf("\nEnter n: ");
}

return 0;
}

// 函数定义
// 功能：输出两维数组x中的数据，数据项n行、n列
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)
x[i][j]=i+1;
for(i=0;i<n;++i)
for(j=0;j<n;++j)
x[j][i]=x[i][j];
}

 

 

 

 六

#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);

    // 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;
}

 

 七

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

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