HW 11

Problem A: 输出数组

题面：

main函数：

int main()
{
    int k, m, n;
 
    cin >> k;
    MyArray<string> s(k);
    for(int i = 0; i < k; i++)
        cin >> s[i];
 
    cin >> m >> n;
    cout << s[m];
    for(int i = m + 1; i <= n; i++)
        cout << " " << s[i];
    cout << endl;
 
    cin >> k;
    MyArray<int> a(k);
    for(int i = 0; i < k; i++)
        cin >> a[i];
 
    cin >> m >> n;
    cout << a[m];
    for(int i = m + 1; i <= n; i++)
        cout << " " << a[i];
    cout << endl;
}

考点：下标运算符的重载，vector的使用。

AC代码：

#include <iostream>
#include <vector>
using namespace std;
template<class T>
class MyArray
{
    vector<T> arr;
public:
    MyArray(int k){arr.resize(k);}
    T& operator [](int k)
    {
        return arr[k];
    }
};

Problem B: 循环交换

题面：

main函数：

int main()
{
    int a, b, c, k;
    cin >> a >> b >> c;
    while(cin >> k)
    {
        if(k == 0)
            swp(a, b, c);
        else
            swp(a, b, c, k);
        cout << a << " " << b << " " << c << " " << endl;
    }
}

考点：传引用，默认参数，还有算是swap的灵活应用吧，对于a,b,c三个数，左移 = (swap(a,b)+swap(b,c))；右移 = (swap(b,c)+swap(a,b))。

AC代码：

#include <iostream>
#include <algorithm>
using namespace std;
void swp(int &a,int &b,int &c,int k = 0 )
{
    if(k==0)
    {
        swap(a,b);
        swap(b,c);
    }
    else
    {
        for(int i = 0;i<k;i++)
        {
            swap(b,c);
            swap(a,b);
        }
    }
}

Problem C: 薪酬计算 之二

题面：

main函数：

int main()
{
    string label, name;
    Employee* p[100];
    int n;
    int base, royalty, bonus;
    cin >> n;
    for(int i = 0; i < n; i++)
    {
        cin >> label >> name;
        if(label == "Sales")
        {
            cin >> base >> royalty;
            p[i] = new Sales(name, base, royalty);
        }
        if(label == "Manager")
        {
            cin >> base >> bonus;
            p[i] = new Manager(name, base, bonus);
        }
        if(label == "SalesManager")
        {
            cin >> base >> royalty >> bonus;
            p[i] = new SalesManager(name, base, royalty, bonus);
        }
    }
    for(int i = 0; i < n; i++)
        p[i]->print();
    for(int i = 0; i < n; i++)
        delete p[i];
}

考点：类的继承,虚基类

AC代码:

#include <string>
#include <iostream>
using namespace std;
class Employee
{
    friend class Sales;
    friend class Manager;
    friend class SalesManager;
    string name ;
    int base;
public:
    Employee(string _name,int _b):name(_name),base(_b){}
    virtual void print()=0;
};
class Sales:public Employee
{
    int ti;
public:
    Sales(string _n,int _b,int _r):Employee(_n,_b),ti(_r){}
    void print()
    {
        cout << "Sales ";
        cout << name;
        cout << " : "  <<(ti+base)*12 << endl;
    }
};
class Manager:public Employee
{
    int ti;
public:
    Manager(string _n,int _b,int _r):Employee(_n,_b),ti(_r){}
    void print()
    {
        cout << "Manager ";
        cout << name;
        cout << " : "  <<base*12+ti << endl;
    }
};
class SalesManager:public Employee
{
    int ti,b;
public:
    SalesManager(string _n,int _b,int _r,int _s):Employee(_n,_b),ti(_r),b(_s){}
    void print()
    {
        cout << "SalesManager ";
        cout << name;
        cout << " : "  <<(ti+base)*12+b << endl;
    }
};

Problem D: 儿童绘画游戏

题面：

main函数：

int main()
{
    cout<<"In beginning, "<<User::getCntOfUsers()<<" users,";
    cout<<Shape::getCntOfShapes()<<" shapes."<<endl;
    User tmp("C++");
    tmp.addAShape(1, 1, 2);
    tmp.addAShape(2, 3);
    cout<<tmp.getArea()<<endl;
 
    UserList lst;
    string s1;
    cin>>lst;
    cout<<"Now, "<<User::getCntOfUsers()<<" users,";
    cout<<Shape::getCntOfShapes()<<" shapes, including ";
    cout<<Circle::getCntOfCircles()<<" circles, and ";
    cout<<Rectangle::getCntOfRects()<<" rectangles."<<endl;
    cout<<lst;
    while(cin>>s1)
    {
        lst.showTotalArea(s1);
    }
    return 0;
}

考点：静态数据成员，虚基类，输入输出流的重载。

AC代码：

#include <iostream>
#include <vector>
#include <typeinfo>
using namespace std;
const double PI = 3.14;
class Shape
{
    static int CntOfShapes;
public:
    Shape(){CntOfShapes++;}
    virtual double getArea()=0;
    static int getCntOfShapes()
    {
        return CntOfShapes;
    }
    virtual void print()=0;
    virtual ~Shape(){};
};
class UserList;
class Rectangle:public Shape
{

    double length,width;
    static int CntOfRects;
public:
    Rectangle(double _length,double _width):Shape(),length(_length),width(_width){CntOfRects++;}
    double getArea()
    {
        return length*width;
    }
    static int getCntOfRects()
    {
        return CntOfRects;
    }
    void print()
    {
        cout << "rect(" << length << "," << width << ")";
    }
    friend istream& operator >> (istream& in,UserList& ul);
    friend ostream& operator << (ostream& out,const UserList& ul);
    ~Rectangle(){}
};
class Circle:public Shape
{
    double radius;
    static int CntOfCircles;
public:
    Circle(double _radius):Shape(),radius(_radius){CntOfCircles++;}
    static int getCntOfCircles()
    {
        return CntOfCircles;
    }
    double getArea()
    {
        return PI*radius*radius;
    }
    void print()
    {
        cout << "Circle(" << radius << ")";
    }
    friend istream& operator >> (istream& in,UserList& ul);
    friend ostream& operator << (ostream& out,const UserList& ul);
    ~Circle(){}
};

class User
{
    friend class UserList;
    string name;
    vector<Shape*> ShapeList;
    static int CntOfUsers;
public:
    User(){}
    User(string _name):name(_name){CntOfUsers++;}
    static int getCntOfUsers()
    {
        return CntOfUsers;
    }
    void addAShape(int t,double a,double b = 0)
    {
        if(t==1)
            ShapeList.push_back(new Rectangle(a,b));
        else
            ShapeList.push_back(new Circle(a));
    }
    double getArea()
    {
        double ans = 0;
        int len = ShapeList.size();
        for(int i = 0;i<len;i++)
        {
            ans += ShapeList[i]->getArea();
        }
        return ans;
    }
    friend istream& operator >> (istream& in,UserList& ul);
    friend ostream& operator << (ostream& out,const UserList& ul);
    ~User(){}
};
class UserList
{
    vector<User*> Userlist;
public:
    void showTotalArea(string name)
    {
        int len = Userlist.size();
        for(int i = 0;i<len;i++)
        {
            if(Userlist[i]->name == name)
            {
                cout << Userlist[i]->getArea() << endl;
                return ;
            }
        }
        cout << "The user ";
        cout << name;
        cout << " doesn't exist." << endl;
        return ;
    }
    friend istream& operator >> (istream& in,UserList& ul);
    friend ostream& operator << (ostream& out,const UserList& ul);
};
istream& operator >> (istream& in,UserList& ul)
{
    int N,M,t;
    double a,b;
    in >> N;
    ul.Userlist.resize(N);
    for(int i = 0;i<N;i++)
    {
        ul.Userlist[i] = new User;
        in >> ul.Userlist[i]->name;
        in >> M;
        for(int j = 0;j<M;j++)
        {
            //cout << "Begin" << endl;
            in >> t;
            if(t==1)
            {
                in >> a >> b;
                ul.Userlist[i]->addAShape(t,a,b);
            }
            else
            {
                in >> a;
                ul.Userlist[i]->addAShape(t,a);
            }
           // cout << "END" << endl;
        }
    }
    return in;
}
ostream& operator << (ostream& out,const UserList& ul)
{
    int len = ul.Userlist.size();
    for(int i = 0;i<len;i++)
    {
        out << ul.Userlist[i]->name;
        out << " : ";
        int len1 = ul.Userlist[i]->ShapeList.size();
        for(int j = 0;j<len1;j++)
        {
            ul.Userlist[i]->ShapeList[j]->print();
            if(j!=len1-1)
                out << ",";
            else
                out << "
";
        }
    }
    return out;
}
int Shape::CntOfShapes = 0;
int Rectangle::CntOfRects = 0;
int Circle::CntOfCircles = 0;
int User::CntOfUsers = 0;

略有不同的另一个版本：

#include <iostream>
#include <vector>
#include <typeinfo>
using namespace std;
const double PI = 3.14;
class Shape
{
    static int CntOfShapes;
public:
    Shape(){CntOfShapes++;}
    virtual double getArea()=0;
    static int getCntOfShapes()
    {
        return CntOfShapes;
    }
    virtual ~Shape(){};
};
class UserList;
class Rectangle:public Shape
{

    double length,width;
    static int CntOfRects;
public:
    Rectangle(double _length,double _width):Shape(),length(_length),width(_width){CntOfRects++;}
    double getArea()
    {
        return length*width;
    }
    static int getCntOfRects()
    {
        return CntOfRects;
    }
    friend istream& operator >> (istream& in,UserList& ul);
    friend ostream& operator << (ostream& out,const UserList& ul);
    ~Rectangle(){}
};
class Circle:public Shape
{
    double radius;
    static int CntOfCircles;
public:
    Circle(double _radius):Shape(),radius(_radius){CntOfCircles++;}
    static int getCntOfCircles()
    {
        return CntOfCircles;
    }
    double getArea()
    {
        return PI*radius*radius;
    }
    friend istream& operator >> (istream& in,UserList& ul);
    friend ostream& operator << (ostream& out,const UserList& ul);
    ~Circle(){}
};

class User
{
    friend class UserList;
    string name;
    vector<Shape*> ShapeList;
    static int CntOfUsers;
public:
    User(){}
    User(string _name):name(_name){CntOfUsers++;}
    static int getCntOfUsers()
    {
        return CntOfUsers;
    }
    void addAShape(int t,double a,double b = 0)
    {
        if(t==1)
            ShapeList.push_back(new Rectangle(a,b));
        else
            ShapeList.push_back(new Circle(a));
        //cout << 1 << endl;
    }
    double getArea()
    {
        double ans = 0;
        int len = ShapeList.size();
        for(int i = 0;i<len;i++)
        {
            ans += ShapeList[i]->getArea();
        }
        return ans;
    }
    friend istream& operator >> (istream& in,UserList& ul);
    friend ostream& operator << (ostream& out,const UserList& ul);
    ~User(){}
};
class UserList
{
    vector<User*> Userlist;
public:
    void showTotalArea(string name)
    {
        int len = Userlist.size();
        for(int i = 0;i<len;i++)
        {
            if(Userlist[i]->name == name)
            {
                cout << Userlist[i]->getArea() << endl;
                return ;
            }
        }
        cout << "The user ";
        cout << name;
        cout << " doesn't exist." << endl;
        return ;
    }
    friend istream& operator >> (istream& in,UserList& ul);
    friend ostream& operator << (ostream& out,const UserList& ul);
};
istream& operator >> (istream& in,UserList& ul)
{
    int N,M,t;
    double a,b;
    in >> N;
    ul.Userlist.resize(N);
    for(int i = 0;i<N;i++)
    {
        ul.Userlist[i] = new User;
        in >> ul.Userlist[i]->name;
        in >> M;
        for(int j = 0;j<M;j++)
        {
            //cout << "Begin" << endl;
            in >> t;
            if(t==1)
            {
                in >> a >> b;
                ul.Userlist[i]->addAShape(t,a,b);
            }
            else
            {
                in >> a;
                ul.Userlist[i]->addAShape(t,a);
            }
           // cout << "END" << endl;
        }
    }
    return in;
}
ostream& operator << (ostream& out,const UserList& ul)
{
    int len = ul.Userlist.size();
    for(int i = 0;i<len;i++)
    {
        out << ul.Userlist[i]->name;
        out << " : ";
        int len1 = ul.Userlist[i]->ShapeList.size();
        for(int j = 0;j<len1;j++)
        {
            if(typeid(*(ul.Userlist[i]->ShapeList[j]))==typeid(Rectangle))
            {
                out << "rect(" << ((Rectangle*)(ul.Userlist[i]->ShapeList[j]))->length << "," << ((Rectangle*)(ul.Userlist[i]->ShapeList[j]))->width << ")";
            }
            else
            {
                out << "circle(" << ((Circle*)(ul.Userlist[i]->ShapeList[j]))->radius << ")" ;
            }
            if(j!=len1-1)
                out << ",";
            else
                out << "
";
        }
    }
    return out;
}
int Shape::CntOfShapes = 0;
int Rectangle::CntOfRects = 0;
int Circle::CntOfCircles = 0;
int User::CntOfUsers = 0;

Problem E: 向量的删除

main函数：

int main()
{
    Vec v1, v2, v3;
    cin>>v1;
    cin>>v2;
    cout<<"v1:"<<v1;
    cout<<"v2:"<<v2;
    v3 = v1 - v2;
    cout<<"v1:"<<v1;
    cout<<"v2:"<<v2;
    cout<<"v3:"<<v3;
    return 0;
}

考点：set的使用，输入输出运算符的重载。

AC代码：

#include <iostream>
#include <set>
#include <algorithm>
using namespace std;
class Vec
{
public:
    Vec() {}
    set<int> s;
    Vec(set<int>c):s(c) {};
    friend istream &operator >> (istream &is,Vec&b);
    friend ostream& operator<< (ostream &os,Vec &b);
    Vec operator -(Vec &b)
    {
        set<int>c;
        set_difference(s.begin(),s.end(),b.s.begin(),b.s.end(),inserter(c, c.begin()));
        return Vec(c);
    }
};
istream &operator >> (istream &is,Vec&b)
{
    int a,k;
    is >> a;
    for(int i = 0; i<a; i++)
    {
        is>> k;
        b.s.insert(k);
    }
    return is;
}
ostream& operator<< (ostream &os,Vec &b)
{
    if(b.s.size()==0)
    {
        os<< endl;
        return os;
    }
    set<int>::iterator it = b.s.begin();
    os << *it;
    it++;
    for(it; it!=b.s.end(); ++it)
        os << " " << *it;
    os << endl;
    return os;
}

Problem F: 字符串折叠

题面：

main函数：

int main()
{
    MyString str;
    int n, i;
    cin>>n;
    for (i = 0; i < n; i++)
    {
        str.input();
        str.output();
    }
    return 0;
}

考点：回文串的判断。

AC代码：

#include <string>
#include <iostream>

using namespace std;
bool ok(string s)
{
    int len = s.size();
    for(int i = 0,j=len-1;i<=j;i++,j--)
        if(s[i]!=s[j])
            return false;
    return true;
}
class MyString
{
public:
    string s;
    void input()
    {
        cin >> s;
    }
    void output()
    {
        if(ok(s))
        {
            int len =s.size();
            for(int i = 0 ;i<(len+1)/2;i++)
                cout << s[i];
            cout << endl;
        }
        else
            cout << s << endl;
    }
};

Problem G: 汽车、客车、货车

题面：

main函数：

int main()
{
    int w, g;
    char t;
    Vehicle *veh;
    while (cin>>w>>t>>g)
    {
        if (t == 'b')
        {
            veh = new Bus(w, g);
        }
        else
        {
            veh = new Truck(w, g);
        }
        delete veh;
    }
    return 0;
}

考点：类的继承

AC代码：

#include <cstdio>
#include <algorithm>
#include <iostream>
using namespace std;
class Vehicle
{
public:
    int num;
    Vehicle(int n):num(n)
    {
        printf("Vehicle has %d wheels is created.
",num);
    }
    virtual ~Vehicle()
    {
        printf("Vehicle has %d wheels is erased.
",num);
    }
};
class Bus:public Vehicle
{
public:
    int w;
    Bus(int _n,int _w):Vehicle(_n),w(_w)
    {
        printf("Bus which can carry %d persons is created.
",w);
    }
    ~Bus()
    {
        printf("Bus which can carry %d persons is erased.
",w);
    }
};
class Truck:public Vehicle
{
public:
    int w;
    Truck(int _n,int _w):Vehicle(_n),w(_w)
    {
        printf("Truck which can carry %d tons goods is created.
",w);
    }
    ~Truck()
    {
        printf("Truck which can carry %d tons goods is created.
",w);
    }
};

Problem H: 不一样的奇偶性

main函数：

int main()
{
    int i;
    while(cin>>i)
    {
        Integer INT(i);
        if (INT.judge())
            cout<<"YES"<<endl;
        else
            cout<<"NO"<<endl;
    }
    return 0;
}

 考点：类的使用

AC代码：

#include <iostream>
using namespace std;
class Integer
{
public:
    int data;
    Integer(int _d):data(_d){}
    bool judge()
    {
        int d  = data;
        int num = 0;
        while(d)
        {
            num+=(d%10);
            d/=10;
        }
        if(num%2==0)
            return false;
        else
            return true;
    }
};

Problem I: 今年多少岁

main函数：

int main()
{
    int y, m, d;
    string name;
    cin>>y>>m>>d>>name;
    Person person(y, m, d, name);
    person.show();
    cin>>y>>m>>d;
    Date now(y,m,d);
    cout<<"Now, "<<person.getName()<<" is "<<person.getAge(now)<<"."<<endl;
    return 0;
}

考点：类的使用（注意周岁的计算 ，只用算年的差）

AC代码：

#include <cstdio>
#include <iostream>
#include <string>
using namespace std;
class Date
{
public:
    int y,m,d;
    Date(int _y,int _m,int _d):y(_y),m(_m),d(_d)
    {
        printf("Date %d-%d-%d is created.
",y,m,d);
    }
    ~Date()
    {
        printf("Date %d-%d-%d is erased.
",y,m,d);
    }
 
};
class Person
{
public:
    Date bir;
    string name;
    Person(int y,int m,int d,string _s):bir(y,m,d),name(_s)
    {
        cout << "Person " <<name << " is created." << endl;
    }
    ~Person()
    {
        cout << "Person " <<name << " is erased." << endl;
    }
    int getAge(Date &b)
    {
        int d = b.y-bir.y;
        return d;
    }
    void show()
    {
        cout << name << "'s birthday is " ;
        printf("%d-%d-%d.
",bir.y,bir.m,bir.d);
    }
    string getName()
    {
        return name;
    }
};

Problem J: 逻辑表达式

main函数：

int main()
{
    int a, b;
    char ch;
    while (cin>>a>>ch>>b)
    {
        Logical log(a, b, ch);
        log.show();
    }
    return 0;
}

考点：逻辑运算符

AC代码：

#include <iostream>
#include <cstdio>
using namespace std;
class Logical
{
public:
    int a,b;
    char op;
    Logical(int _a, int _b, char _op):a(_a),b(_b),op(_op){}
    void show()
    {
        int d ;
        printf("%d %c %d = ",a,op,b);
        if(op=='+')
        {
           if(a!=b)
                d = 1;
           else
                d = 0;
        }
        else if(op=='-')
           {
               if(a==b)
                    d = 1;
               else
                d = 0;
           }
        else if(op=='*')
            d = (a&&b);
        else if(op=='/')
            d = (a||b);
        printf("%d
",d);
    }
};