初步完成第四题

homework1/CMakeLists.txt

@@ -7,3 +7,4 @@ add_executable(test1
         test1.cpp)
 add_executable(test2 test2.cpp)
 add_executable(test3 test3.cpp)
+add_executable(test4 test4.cpp)

homework1/test4.cpp

@@ -0,0 +1,68 @@
+#include <iostream>
+#include <iomanip>
+
+using namespace std;
+
+typedef struct {
+    string id;
+    string name;
+    double price;
+} book;
+
+typedef struct {
+    book books[];
+    int number_of_books;
+} book_and_number;
+
+double max_price(book *books, int n) {
+    double max_price = 0;
+    for (int i = 0; i < n; i++) {
+        if (books[i].price > max_price) {
+            max_price = books[i].price;
+        }
+    }
+    return max_price;
+}
+
+book_and_number max_price_books(book *books, int n) {
+    double max_price = max_price(books, n);
+
+    book_and_number books_and_number;
+    book max_price_books[];
+
+    books_and_number.number_of_books = 0;
+    for (int i = 0; i < n; i++) {
+        if (books[i].price == max_price) {
+            max_price_books[i] = books[i];
+            books_and_number.number_of_books++;
+        }
+    }
+    books_and_number.books = &max_price_books;
+    return books_and_number;
+}
+
+void input(book *books, int n) {
+    for (int i = 0; i < n; i++) {
+        cin >> books[i].id >> books[i].name >> books[i].price;
+    }
+}
+
+void output(book_and_number books_and_number) {
+    cout << books_and_number.number_of_books << endl;
+    for (int i = 0; i < books_and_number.number_of_books; i++) {
+        cout << books_and_number.books[i].id << "\t" << books_and_number.books[i].name << "\t" << fixed <<
+                setprecision(2) <<
+                books_and_number.books[i].price << endl;
+    }
+}
+
+int main() {
+    book books[100];
+    int n;
+    cin >> n;
+    input(books, n);
+    max_price(books, n);
+    book_and_number books_and_number = max_price_books(books, n);
+    output(books_and_number);
+    return 0;
+}