114 一般警察特考三等 警察資訊管理人員類別 物件導向程式設計 考古題詳解

針對下列 C++ 程式碼，請說明其輸出與其程式 p.print()、q.split()（Line 28、29）執行之運作流程邏輯；並請說明在 testPattern() 中測試 Pattern 類別 split()（Line 27、29），對於「指令與條件判斷涵蓋度」不足之處。

#include <iostream> #include <string> #include <vector> using namespace std;

class Pattern { public: Pattern(string data) { this->data = data; }

void split(string symbol) {
    int start = 0, stop = 0;
    stop = data.find(symbol);

    while (stop != string::npos) {
        if (stop != start)
            words.push_back(data.substr(start, stop - start));

        start = stop + symbol.size();
        stop = data.find(symbol, start);
    }

    if (start != length)
        words.push_back(data.substr(start));
}

void print() {
    for (auto& s : words)
        cout << s << "#";
    cout << endl;
}

private: string data; vector<string> words; int length; };

void testPattern() { Pattern p("this is a test"); Pattern q("that was so happle");

p.split(" ");
p.print();

q.split("ha");
q.print();

}

int main() { testPattern(); return 0; }

下列 Java 程式碼計算食物（Food）料理（cook）後，動物（Animal）攝取之卡路里量。請完成統一塑模語言 UML 圖；並說明其執行後的輸出，以及多型（Polymorphism）、封裝（Encapsulation）發生所在之程式碼行數。

🖼️【此處有附 UML 類別圖，請對照原卷】

abstract class Food { public Food(int cal, String type) { this.calorie = cal; this.type = type; }

abstract public void cook(int c);

public String show(int c) {
    String result = type + ":";
    cook(c);
    result += calorie;
    return result;
}

protected int calorie;    // 卡路里
private String type;

}

class Bread extends Food { public Bread(int c, int a) { super(c, "Bread"); additives = a; }

public void cook(int cal) {
    calorie += additives * cal;
}

private int additives;

}

class Beef extends Food { public Beef(int c) { super(c, "Beef"); condiments = c * 2; }

public void cook(int cal) {
    calorie += condiments % cal;
}

private int condiments;

}

class Animal { public Animal(Food f) { food = f; }

public String getCal() {
    return food.show(2);
}

private Food food;

}

public class FoodTest { public static void main(String[] args) { Food f1 = new Bread(3, 2); Food f2 = new Bread(2, 3); Food f3 = new Beef(3);

    Animal a1 = new Animal(f1);
    Animal a2 = new Animal(f2);
    Animal a3 = new Animal(f3);

    System.out.println(a1.getCal());
    System.out.println(a2.getCal());
    System.out.println(a3.getCal());
}

}

針對下列 C++ 程式碼，請修正程式碼行數 58「Job jobs ...」的錯誤及修正錯誤後正確執行之輸出；並請說明 Employee 類別 candidate 資料的運作原理，以及程式碼行數 61「e1.arrange()」程式執行之流程。

#include <iostream> #include <string> #include <map> using namespace std;

class Job { public: Job(string _name, int _sa, int _sk) { name = _name; salary = _sa; skill = _sk; employee_name = "None"; }

string getName() { return name; }
int getSalary() { return salary; }
int getSkill() { return skill; }
void hire(string _name) { employee_name = _name; }

void print() {
    cout << name << ":" << employee_name << endl;
}

private: string name; int salary; int skill; string employee_name; };

class Employee { public: Employee(string _name, int _sa, int _sk) { name = _name; salary = _sa; skill = _sk; }

void match(Job *m) {
    if ((m->getSalary() >= salary) && (skill >= m->getSkill())) {
        candidate[m->getName()] = m;
    }
}

void arrange() {
    int score = 0;
    Job *jb, *jb_wanted;

    for (auto c = candidate.begin(); c != candidate.end(); ++c) {
        jb = c->second;    // get value of MAP

        if (jb->getSalary() >= score) {
            score = jb->getSalary();
            jb_wanted = jb;
        }
    }

    jb_wanted->hire(name);
}

string getName() { return name; }

private: string name; int salary; int skill; map<string, Job *> candidate; };

int main() { Employee e1("Tom", 37, 85); Employee e2("John", 35, 75);

Job jobs[] = {
    new Job("RD", 45, 75),
    new Job("Sales", 35, 70),
    new Job("Manager", 55, 80)
};

for (int i = 0; i < 3; i++)
    e1.match(jobs[i]);

e1.arrange();

for (int i = 0; i < 3; i++)
    e2.match(jobs[i]);

e2.arrange();

for (int i = 0; i < 3; i++)
    jobs[i]->print();

return 0;

}

針對下列 C++ 程式碼，請說明其輸出與其 inpuScore()、computeAverage() 執行之運作流程邏輯；並請說明 computeAverage() 設計上的問題。

#include <stdexcept> #include <iostream> #include <string> using namespace std;

class Student { public: Student(string n) { name = n; math_score = eng_score = average = 0; }

void checkSmall(int s) {
    if (s <= 0)
        throw out_of_range("small");
    cout << "ok,";
}

void inpuScore(int m_s, int e_s) {
    try {
        checkSmall(m_s);
        checkSmall(e_s);
        math_score = m_s;
        eng_score = e_s;
    }
    catch (exception &e) {
        cout << e.what() << endl;
    }
}

void computeAverage(int n) {
    try {
        if (n <= 0)
            throw out_of_range("zero");

        average = (math_score + eng_score) / n;
    }
    catch (exception &e) {
        cout << "exc" << endl;
    }
    catch (out_of_range &e) {
        cout << e.what() << endl;
    }
}

void print() {
    cout << name << ":" << average << endl;
}

private: int math_score; // 數學成績 int eng_score; // 英文成績 int average; // 平均成績 string name; };

void test01() { Student stu("John");

stu.inpuScore(0, 0);
stu.inpuScore(100, -1);
stu.inpuScore(100, 90);
stu.print();

}

void test02() { Student stu("Tom");

stu.inpuScore(100, 90);
stu.computeAverage(0);
stu.print();

}

int main() { test01(); test02(); return 0; }