高级程序设计语言第八次个人作业
| 这个作业属于哪个课程 | <班级的链接> |
|---|---|
| 这个作业要求在哪里 | <作业链接> |
| 学号 | 092300303 |
| 姓名 | 池博洋 |
@
11.13
1
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#include <stdio.h>
char *get_n_chars(char *str, int n) {
int i = 0;
char ch;
printf("请输入最多 %d 个字符（包括空白、制表符、换行符）：\n", n);
while (i < n) {
ch = getchar();
if (ch == EOF) {
break;
}
str[i++] = ch;
}
str[i] = '\0';
return str;
}
int main() {
char str[100];
int n;
printf("请输入要读取的字符数：");
scanf("%d", &n);
getchar(); // 清除换行符
get_n_chars(str, n);
printf("你输入的内容是：\n%s\n", str);
return 0;
}
结果：
2
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#include <stdio.h>
char *get_n_chars_mod(char *str, int n) {
int i = 0;
char ch;
printf("请输入字符（最多 %d 个字符，或遇到空白、制表符、换行符停止）：\n", n);
while (i < n) {
ch = getchar();
if (ch == EOF || ch == ' ' || ch == '\t' || ch == '\n') {
break;
}
str[i++] = ch;
}
str[i] = '\0';
// 如果停止是因为空白字符，需要清除输入缓冲区中的剩余字符
if (ch != EOF && ch != '\n' && ch != ' ' && ch != '\t') {
while (getchar() != '\n') {
continue;
}
}
return str;
}
int main() {
char str[100];
int n;
printf("请输入最大字符数：");
scanf("%d", &n);
getchar(); // 清除换行符
get_n_chars_mod(str, n);
printf("读取的结果是：\"%s\"\n", str);
return 0;
}
结果：
3
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#include <stdio.h>
#include <ctype.h>
char *get_word(char *str) {
char ch;
int i = 0;
printf("请输入一行文本：\n");
// 跳过前面的空白字符
while ((ch = getchar()) != EOF && isspace(ch)) {
continue;
}
// 如果第一个非空白字符是EOF，返回空字符串
if (ch == EOF) {
str[0] = '\0';
return str;
}
// 读取单词直到遇到空白字符
do {
str[i++] = ch;
} while ((ch = getchar()) != EOF && !isspace(ch));
str[i] = '\0';
// 丢弃输入行中的其余字符
if (ch != EOF && ch != '\n') {
while (getchar() != '\n') {
continue;
}
}
return str;
}
int main() {
char str[100];
printf("=== 单词读取测试 ===\n");
get_word(str);
printf("读取的单词是：\"%s\"\n", str);
return 0;
}
结果：
6
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#include <stdio.h>
int is_within(char ch, const char *str) {
while (*str) {
if (*str == ch) {
return 1; // 找到字符，返回真
}
str++;
}
return 0; // 未找到字符，返回假
}
int main() {
char str[100];
char ch;
char choice;
do {
printf("请输入一个字符串：");
fgets(str, sizeof(str), stdin);
// 移除fgets读取的换行符
int i = 0;
while (str[i] != '\n' && str[i] != '\0') {
i++;
}
str[i] = '\0';
printf("请输入要查找的字符：");
scanf(" %c", &ch);
getchar(); // 清除换行符
if (is_within(ch, str)) {
printf("字符 '%c' 在字符串 \"%s\" 中\n", ch, str);
} else {
printf("字符 '%c' 不在字符串 \"%s\" 中\n", ch, str);
}
printf("是否继续测试？(y/n): ");
scanf(" %c", &choice);
getchar(); // 清除换行符
} while (choice == 'y' || choice == 'Y');
printf("测试结束\n");
return 0;
}
结果：
7
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#include <stdio.h>
#include <string.h>
char *mystrncpy(char *s1, const char *s2, int n) {
int i;
// 拷贝字符
for (i = 0; i < n && s2[i] != '\0'; i++) {
s1[i] = s2[i];
}
// 如果拷贝的字符数小于n，且s2长度小于n，则添加空字符
// 注意：标准strncpy在s2长度>=n时不会添加空字符
if (i < n && s2[i] == '\0') {
s1[i] = '\0';
}
return s1;
}
int main() {
char src[100], dest[100];
int n;
char choice;
do {
printf("请输入源字符串：");
fgets(src, sizeof(src), stdin);
// 移除fgets读取的换行符
int i = 0;
while (src[i] != '\n' && src[i] != '\0') {
i++;
}
src[i] = '\0';
printf("请输入要拷贝的字符数：");
scanf("%d", &n);
getchar(); // 清除换行符
// 使用自定义函数拷贝
mystrncpy(dest, src, n);
// 确保dest以空字符结尾（当n小于dest大小时）
if (n < sizeof(dest)) {
dest[n] = '\0';
} else {
dest[sizeof(dest) - 1] = '\0';
}
printf("源字符串: \"%s\"\n", src);
printf("拷贝 %d 个字符到目标字符串: \"%s\"\n", n, dest);
printf("是否继续测试？(y/n): ");
scanf(" %c", &choice);
getchar(); // 清除换行符
} while (choice == 'y' || choice == 'Y');
printf("测试结束\n");
// 额外的对比测试
printf("\n=== 与标准strncpy函数的对比测试 ===\n");
char test_src[] = "Hello World!";
char my_dest[20], std_dest[20];
// 测试1：拷贝少于源字符串长度的字符
mystrncpy(my_dest, test_src, 5);
my_dest[5] = '\0';
strncpy(std_dest, test_src, 5);
std_dest[5] = '\0';
printf("测试1（拷贝5个字符）:\n");
printf("mystrncpy结果: \"%s\"\n", my_dest);
printf("strncpy结果 : \"%s\"\n", std_dest);
// 测试2：拷贝等于源字符串长度的字符
mystrncpy(my_dest, test_src, 13);
strncpy(std_dest, test_src, 13);
printf("\n测试2（拷贝13个字符）:\n");
printf("mystrncpy结果: \"%s\"\n", my_dest);
printf("strncpy结果 : \"%s\"\n", std_dest);
return 0;
}
结果：
12.9
1
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#include <stdio.h>
// 函数原型声明
void critic(int *units_ptr);
int main(void)
{
int units; // 局部变量
printf("How many pounds to a firkin of butter?\n");
scanf("%d", &units);
// 当猜错时，调用critic函数
while (units != 56) {
critic(&units); // 传递units的地址
}
printf("You must have looked it up!\n");
return 0;
}
void critic(int *units_ptr)
{
printf("No luck, my friend. Try again.\n");
scanf("%d", units_ptr); // 直接修改main中的units
}
结果：
2
头文件
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/* p12-2a.h -- 油耗计算程序头文件 */
#ifndef P12_2A_H
#define P12_2A_H
/* 文件作用域变量声明 */
extern int mode; // 0=公制，1=美制
extern float distance; // 行驶距离
extern float fuel; // 消耗的燃油
/* 函数原型 */
void set_mode(int m);
void get_info(void);
void show_info(void);
#endif
源文件
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/* p12-2a.c -- 油耗计算程序实现 */
#include <stdio.h>
#include "p12-2a.h"
/* 文件作用域变量定义 */
int mode = 0; // 默认使用公制模式
float distance = 0;
float fuel = 0;
/* 设置模式函数 */
void set_mode(int m)
{
static int last_mode = 0; // 上一次有效的模式
if (m == 0 || m == 1) {
mode = m;
last_mode = m;
} else {
printf("Invalid mode specified. Mode %d(%s) used.\n",
last_mode, last_mode == 0 ? "metric" : "US");
mode = last_mode;
}
}
/* 获取信息函数 */
void get_info(void)
{
if (mode == 0) {
// 公制模式：升/100公里
printf("Enter distance traveled in kilometers: ");
while (scanf("%f", &distance) != 1 || distance <= 0) {
printf("Please enter a positive number: ");
while (getchar() != '\n') continue; // 清理输入缓冲区
}
printf("Enter fuel consumed in liters: ");
while (scanf("%f", &fuel) != 1 || fuel <= 0) {
printf("Please enter a positive number: ");
while (getchar() != '\n') continue;
}
} else {
// 美制模式：英里/加仑
printf("Enter distance traveled in miles: ");
while (scanf("%f", &distance) != 1 || distance <= 0) {
printf("Please enter a positive number: ");
while (getchar() != '\n') continue;
}
printf("Enter fuel consumed in gallons: ");
while (scanf("%f", &fuel) != 1 || fuel <= 0) {
printf("Please enter a positive number: ");
while (getchar() != '\n') continue;
}
}
}
/* 显示信息函数 */
void show_info(void)
{
if (mode == 0) {
// 公制模式：计算升/100公里
float consumption = (fuel / distance) * 100;
printf("Fuel consumption is %.2f liters per 100 km.\n", consumption);
} else {
// 美制模式：计算英里/加仑
float consumption = distance / fuel;
printf("Fuel consumption is %.1f miles per gallon.\n", consumption);
}
}
主程序
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/* main.c -- 油耗计算主程序 */
#include <stdio.h>
#include "p12-2a.h"
int main(void)
{
int user_mode;
printf("Enter 0 for metric mode, 1 for US mode: ");
scanf("%d", &user_mode);
while (user_mode >= 0) {
set_mode(user_mode);
get_info();
show_info();
printf("\nEnter 0 for metric mode, 1 for US mode (-1 to quit): ");
scanf("%d", &user_mode);
}
printf("Done.\n");
return 0;
}
3
头文件
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/* p12-3.h -- 油耗计算程序头文件（使用自动变量） */
#ifndef P12_3_H
#define P12_3_H
/* 函数原型 */
void set_mode_local(int m, int *mode);
void get_info_local(int mode, float *distance, float *fuel);
void show_info_local(int mode, float distance, float fuel);
#endif
源文件
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/* p12-3.c -- 油耗计算程序实现（使用自动变量） */
#include <stdio.h>
#include "p12-3.h"
/* 设置模式函数（使用自动变量） */
void set_mode_local(int m, int *mode)
{
static int last_mode = 0; // 静态局部变量，记录上一次有效模式
if (m == 0 || m == 1) {
*mode = m;
last_mode = m;
} else {
printf("Invalid mode specified. Mode %d(%s) used.\n",
last_mode, last_mode == 0 ? "metric" : "US");
*mode = last_mode;
}
}
/* 获取信息函数（使用自动变量） */
void get_info_local(int mode, float *distance, float *fuel)
{
if (mode == 0) {
// 公制模式：升/100公里
printf("Enter distance traveled in kilometers: ");
while (scanf("%f", distance) != 1 || *distance <= 0) {
printf("Please enter a positive number: ");
while (getchar() != '\n') continue;
}
printf("Enter fuel consumed in liters: ");
while (scanf("%f", fuel) != 1 || *fuel <= 0) {
printf("Please enter a positive number: ");
while (getchar() != '\n') continue;
}
} else {
// 美制模式：英里/加仑
printf("Enter distance traveled in miles: ");
while (scanf("%f", distance) != 1 || *distance <= 0) {
printf("Please enter a positive number: ");
while (getchar() != '\n') continue;
}
printf("Enter fuel consumed in gallons: ");
while (scanf("%f", fuel) != 1 || *fuel <= 0) {
printf("Please enter a positive number: ");
while (getchar() != '\n') continue;
}
}
}
/* 显示信息函数（使用自动变量） */
void show_info_local(int mode, float distance, float fuel)
{
if (mode == 0) {
// 公制模式：计算升/100公里
float consumption = (fuel / distance) * 100;
printf("Fuel consumption is %.2f liters per 100 km.\n", consumption);
} else {
// 美制模式：计算英里/加仑
float consumption = distance / fuel;
printf("Fuel consumption is %.1f miles per gallon.\n", consumption);
}
}
主程序
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/* main_local.c -- 油耗计算主程序（使用自动变量） */
#include <stdio.h>
#include "p12-3.h"
int main(void)
{
int user_mode;
int current_mode = 0; // 局部变量
float distance = 0; // 局部变量
float fuel = 0; // 局部变量
printf("Enter 0 for metric mode, 1 for US mode: ");
scanf("%d", &user_mode);
while (user_mode >= 0) {
set_mode_local(user_mode, ¤t_mode);
get_info_local(current_mode, &distance, &fuel);
show_info_local(current_mode, distance, fuel);
printf("\nEnter 0 for metric mode, 1 for US mode (-1 to quit): ");
scanf("%d", &user_mode);
}
printf("Done.\n");
return 0;
}
结果：
Enter 0 for metric mode, 1 for US mode: 0
Enter distance traveled in kilometers: 600
Enter fuel consumed in liters: 78.5
Fuel consumption is 13.08 liters per 100 km.
Enter 0 for metric mode, 1 for US mode (-1 to quit): 1
Enter distance traveled in miles: 434
Enter fuel consumed in gallons: 12.7
Fuel consumption is 34.2 miles per gallon.
Enter 0 for metric mode, 1 for US mode (-1 to quit): 3
Invalid mode specified. Mode 1(US) used.
Enter distance traveled in miles: 38
Enter fuel consumed in gallons: 1.5
Fuel consumption is 25.3 miles per gallon.
Enter 0 for metric mode, 1 for US mode (-1 to quit): -1
Done.
8
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#include <stdio.h>
#include <stdlib.h>
/* 函数原型 */
int *make_array(int size, int value);
void show_array(const int arr[], int n);
int main(void)
{
int *pa;
int size;
int value;
printf("Enter the number of elements: ");
while (scanf("%d", &size) == 1 && size > 0) {
printf("Enter the initialization value: ");
scanf("%d", &value);
pa = make_array(size, value);
if (pa) {
show_array(pa, size);
free(pa);
}
printf("\nEnter the number of elements (<1 to quit): ");
}
printf("Done.\n");
return 0;
}
/* 创建并初始化数组的函数 */
int *make_array(int size, int value)
{
int *arr = (int *)malloc(size * sizeof(int));
if (arr != NULL) {
for (int i = 0; i < size; i++) {
arr[i] = value;
}
}
return arr;
}
/* 显示数组内容的函数 */
void show_array(const int arr[], int n)
{
for (int i = 0; i < n; i++) {
printf("%d ", arr[i]);
// 每8个元素换一行
if ((i + 1) % 8 == 0) {
printf("\n");
}
}
// 如果最后一行不满8个，也需要换行
if (n % 8 != 0) {
printf("\n");
}
}
结果：
9
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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main(void)
{
int num_words;
char **words; // 指向指针的指针，用于存储字符串数组
char temp[100]; // 临时缓冲区用于读取单词
// 询问用户需要输入多少个单词
printf("How many words do you wish to enter? ");
scanf("%d", &num_words);
// 分配指针数组
words = (char **)malloc(num_words * sizeof(char *));
if (words == NULL) {
printf("Memory allocation failed!\n");
return 1;
}
// 读取单词
printf("Enter %d words now:\n", num_words);
for (int i = 0; i < num_words; i++) {
scanf("%s", temp);
// 为当前单词分配足够的内存
words[i] = (char *)malloc((strlen(temp) + 1) * sizeof(char));
if (words[i] == NULL) {
printf("Memory allocation failed for word %d!\n", i);
// 释放已分配的内存
for (int j = 0; j < i; j++) {
free(words[j]);
}
free(words);
return 1;
}
// 复制单词到分配的内存
strcpy(words[i], temp);
}
// 显示所有单词
printf("Here are your words:\n");
for (int i = 0; i < num_words; i++) {
printf("%s\n", words[i]);
}
// 释放内存
for (int i = 0; i < num_words; i++) {
free(words[i]);
}
free(words);
return 0;
}
结果：
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