2024年12月完成（补充提交）

2025-03-29 23:02:48 +08:00
commit 4e2bf47db0
@@ -0,0 +1,45 @@
+#include <iostream>
+#include <string>
+#include <vector>
+#include <algorithm>
+#include "split.h"
+
+using std::cin;
+using std::cout;
+using std::endl;
+using std::string;
+using std::vector;
+
+// 函数：反转字符串
+string reverseString(const string& s) {
+    return string(s.rbegin(), s.rend());
+}
+
+int main() {
+    // 读取输入文本
+    cout << "输入一段文本: ";
+    string input;
+    std::getline(cin, input);
+
+    // 拆分文本为单词
+    vector<string> words = split(input);
+
+    // 对每个单词进行反转
+    for (auto& word : words) {
+        word = reverseString(word);
+    }
+
+    // 按照反转后的单词排序
+    std::sort(words.begin(), words.end());
+
+    // 输出排序后的单词，保持与原输入格式一致
+    for (size_t i = 0; i < words.size(); ++i) {
+        if (i > 0) {
+            cout << " "; // 单词间加空格
+        }
+        cout << words[i];
+    }
+    cout << endl;
+
+    return 0;
+}
@@ -0,0 +1,43 @@
+#include <cctype>
+#include <string>
+#include <vector>
+
+#include "split.h"
+
+using std::vector;
+using std::string;
+
+#ifndef _MSC_VER
+using std::isspace;
+#endif
+
+vector<string> split(const string& s)
+{
+	vector<string> ret;
+	typedef string::size_type string_size;
+	string_size i = 0;
+
+	// invariant: we have processed characters `['original value of `i', `i)'
+	while (i != s.size()) {
+		// ignore leading blanks
+		// invariant: characters in range `['original `i', current `i)' are all spaces
+		while (i != s.size() && isspace(s[i]))
+			++i;
+
+		// find end of next word
+		string_size j = i;
+		// invariant: none of the characters in range `['original `j', current `j)' is a space
+		while (j != s.size() && !isspace(s[j]))
+			++j;
+
+		// if we found some nonwhitespace characters
+		if (i != j) {
+			// copy from `s' starting at `i' and taking `j' `\-' `i' chars
+			ret.push_back(s.substr(i, j - i));
+			i = j;
+		}
+
+	}
+	return ret;
+}
+
@@ -0,0 +1,8 @@
+#ifndef GUARD_split_h
+#define GUARD_split_h
+
+#include <vector>
+#include <string>
+std::vector<std::string> split(const std::string&);
+
+#endif
@@ -0,0 +1,41 @@
+#include <iostream>
+#include <string>
+#include <vector>
+#include <algorithm>
+#include "urls.h"
+
+using std::cin;
+using std::cout;
+using std::endl;
+using std::sort;
+using std::string;
+using std::vector;
+
+int main() {
+    // 输入文本
+    cout << "输入一段文本: ";
+    string input;
+    std::getline(cin, input);
+
+    // 提取所有 URL
+    vector<string> urls = find_urls(input);
+
+    // 筛选出以 http:// 或 https:// 开头的 URL
+    vector<string> http_urls;
+    for (const string& url : urls) {
+        if (url.find("http://") == 0 || url.find("https://") == 0) {
+            http_urls.push_back(url);
+        }
+    }
+
+    // 按字母顺序排序
+    sort(http_urls.begin(), http_urls.end());
+
+    // 输出结果
+    cout << "排序后的 HTTP URLs:" << endl;
+    for (const string& url : http_urls) {
+        cout << url << endl;
+    }
+
+    return 0;
+}
@@ -0,0 +1,101 @@
+#include <algorithm>
+#include <cctype>
+#include <string>
+#include <vector>
+
+#include "urls.h"
+
+using std::find;
+using std::find_if;
+
+#ifndef _MSC_VER
+using std::isalnum;
+using std::isalpha;
+using std::isdigit;
+#endif
+
+using std::search;
+using std::string;
+using std::vector;
+
+bool not_url_char(char);
+
+string::const_iterator
+url_end(string::const_iterator, string::const_iterator);
+
+string::const_iterator
+url_beg(string::const_iterator, string::const_iterator);
+vector<string> find_urls(const string& s)
+{
+	vector<string> ret;
+	typedef string::const_iterator iter;
+	iter b = s.begin(), e = s.end();
+
+	// look through the entire input
+	while (b != e) {
+
+		// look for one or more letters followed by `://'
+		b = url_beg(b, e);
+
+		// if we found it
+		if (b != e) {
+			// get the rest of the \s-1URL\s0
+			iter after = url_end(b, e);
+
+			// remember the \s-1URL\s0
+			ret.push_back(string(b, after));
+
+			// advance `b' and check for more \s-1URL\s0s on this line
+			b = after;
+		}
+	}
+	return ret;
+}
+
+string::const_iterator
+url_end(string::const_iterator b, string::const_iterator e)
+{
+	return find_if(b, e, not_url_char);
+}
+
+bool not_url_char(char c)
+{
+	// characters, in addition to alphanumerics, that can appear in a \s-1URL\s0
+	static const string url_ch = "~;/?:@=&$-_.+!*'(),";
+
+	// see whether `c' can appear in a \s-1URL\s0 and return the negative
+	return !(isalnum(c) ||
+	         find(url_ch.begin(), url_ch.end(), c) != url_ch.end());
+}
+
+string::const_iterator
+url_beg(string::const_iterator b, string::const_iterator e)
+{
+	static const string sep = "://";
+
+	typedef string::const_iterator iter;
+
+	// `i' marks where the separator was found
+	iter i = b;
+
+	while ((i = search(i, e, sep.begin(), sep.end())) != e) {
+
+		// make sure the separator isn't at the beginning or end of the line
+		if (i != b && i + sep.size() != e) {
+
+			// `beg' marks the beginning of the protocol-name
+			iter beg = i;
+			while (beg != b && isalpha(beg[-1]))
+				--beg;
+
+			// is there at least one appropriate character before and after the separator?
+			if (beg != i && !not_url_char(i[sep.size()]))
+				return beg;
+		}
+
+		// the separator we found wasn't part of a \s-1URL\s0; advance `i' past this separator
+		i += sep.size();
+	}
+	return e;
+}
+
@@ -0,0 +1,9 @@
+#ifndef GUARD_urls_h
+#define GUARD_urls_h
+
+#include <vector>
+#include <string>
+
+std::vector<std::string> find_urls(const std::string& s);
+
+#endif
@@ -0,0 +1,37 @@
+// source file for `Student_info'-related functions
+#include "Student_info.h"
+
+using std::istream;  using std::vector;
+
+bool compare(const Student_info& x, const Student_info& y)
+{
+	return x.name < y.name;
+}
+
+istream& read(istream& is, Student_info& s)
+{
+	// read and store the student's name and midterm and final exam grades
+	is >> s.name >> s.midterm >> s.final;
+
+	read_hw(is, s.homework);  // read and store all the student's homework grades
+	return is;
+}
+
+// read homework grades from an input stream into a `vector<double>'
+istream& read_hw(istream& in, vector<double>& hw)
+{
+	if (in) {
+		// get rid of previous contents
+		hw.clear();
+
+		// read homework grades
+		double x;
+		while (in >> x)
+			hw.push_back(x);
+
+		// clear the stream so that input will work for the next student
+		in.clear();
+	}
+	return in;
+}
+
@@ -0,0 +1,19 @@
+#ifndef GUARD_Student_info
+#define GUARD_Student_info
+
+// `Student_info.h' header file
+#include <iostream>
+#include <string>
+#include <vector>
+
+struct Student_info {
+	std::string name;
+	double midterm, final;
+	std::vector<double> homework;
+};
+
+bool compare(const Student_info&, const Student_info&);
+std::istream& read(std::istream&, Student_info&);
+std::istream& read_hw(std::istream&, std::vector<double>&);
+#endif
+
@@ -0,0 +1,41 @@
+#include <stdexcept>
+#include <vector>
+#include "grade.h"
+#include "median.h"
+#include "Student_info.h"
+
+using std::domain_error;  using std::vector;
+
+
+// compute a student's overall grade from midterm and final exam grades and homework grade
+double grade(double midterm, double final, double homework)
+{
+	return 0.2 * midterm + 0.4 * final + 0.4 * homework;
+}
+
+// compute a student's overall grade from midterm and final exam grades
+// and vector of homework grades.
+// this function does not copy its argument, because `median' does so for us.
+double grade(double midterm, double final, const vector<double>& hw)
+{
+	if (hw.size() == 0)
+		throw domain_error("student has done no homework");
+	return grade(midterm, final, median(hw));
+}
+
+double grade(const Student_info& s)
+{
+	return grade(s.midterm, s.final, s.homework);
+}
+
+// predicate to determine whether a student failed
+bool fgrade(const Student_info& s)
+{
+	return grade(s) < 60;
+}
+
+bool pgrade(const Student_info& s)
+{
+	return !fgrade(s);
+}
+
@@ -0,0 +1,14 @@
+#ifndef GUARD_grade_h
+#define GUARD_grade_h
+
+#include <vector>
+#include "Student_info.h"
+
+double grade(double, double, double);
+double grade(double, double, const std::vector<double>&);
+double grade(const Student_info&);
+
+bool pgrade(const Student_info&);
+bool fgrade(const Student_info&);
+
+#endif
@@ -0,0 +1,57 @@
+#include <iostream>
+#include <vector>
+#include <algorithm>
+#include "Student_info.h"
+#include "grade.h"
+
+using std::cin;
+using std::cout;
+using std::endl;
+using std::string;
+using std::vector;
+
+// 定义常量：及格分数
+const double PASS_GRADE = 60.0;
+
+int main() {
+    vector<Student_info> students;
+    Student_info record;
+
+    // 读取学生信息
+    cout << "期中成绩占比20%、期末成绩占比40%，平时成绩占比40%）:" << endl;
+    cout << "输入学生信息（姓名、期中成绩、期末成绩，平时成绩）:" << endl;
+    cout << "输入Ctrl+z后回车退出。" << endl;
+
+    while (read(cin, record)) {
+        students.push_back(record);
+    }
+
+    // 将学生分为及格和不及格两组
+    vector<Student_info> pass, fail;
+    for (const auto& student : students) {
+        if (grade(student) >= PASS_GRADE) {
+            pass.push_back(student);
+        }
+        else {
+            fail.push_back(student);
+        }
+    }
+
+    // 按名字排序
+    std::sort(pass.begin(), pass.end(), compare);
+    std::sort(fail.begin(), fail.end(), compare);
+
+    // 输出及格学生信息
+    cout << "合格学生:" << endl;
+    for (const auto& student : pass) {
+        cout << student.name << ": 总成绩 = " << grade(student) << endl;
+    }
+
+    // 输出不及格学生信息
+    cout << "不合格学生:" << endl;
+    for (const auto& student : fail) {
+        cout << student.name << ": 总成绩 = " << grade(student) << endl;
+    }
+
+    return 0;
+}
@@ -0,0 +1,30 @@
+// source file for the `median' function
+#include <algorithm>    // to get the declaration of `sort'
+#include <stdexcept>    // to get the declaration of `domain_error'
+#include <vector>       // to get the declaration of `vector'
+
+using std::domain_error;   using std::sort;   using std::vector;
+
+#include "median.h"
+
+// compute the median of a `vector<double>'
+// note that calling this function copies the entire argument `vector'
+double median(vector<double> vec)
+{
+#ifdef _MSC_VER
+	typedef std::vector<double>::size_type vec_sz;
+#else
+	typedef vector<double>::size_type vec_sz;
+#endif
+
+	vec_sz size = vec.size();
+	if (size == 0)
+		throw domain_error("median of an empty vector");
+
+	sort(vec.begin(), vec.end());
+
+	vec_sz mid = size/2;
+
+	return size % 2 == 0 ? (vec[mid] + vec[mid-1]) / 2 : vec[mid];
+}
+
@@ -0,0 +1,9 @@
+#ifndef GUARD_median_h
+#define GUARD_median_h
+
+// `median.h'--final version
+#include <vector>
+double median(std::vector<double>);
+
+#endif
+