我把时间荒废了，时间便把我荒废了
—— 莎士比亚
Problem A: 建筑物
题面：
main函数：
int main() { Building b; int i; cin>>i; b.setCnt(i); cout<<"The building has "<<b.getCnt()<<" floors."<<endl; return 0; }
考点：类的使用
AC代码：
#include <bits/stdc++.h> using namespace std; class Building { public: int n; void setCnt(int x) { n = x; } int getCnt(){return n;} };
Problem B: 一个人的生日
题面：
main函数：
int main() { string name; int year, month, day; cin>>year>>month>>day; Date date(year, month, day); cin>>name>>year>>month>>day; Person person(year, month, day, name); return 0; }
考点：类的使用
AC代码：
#include <bits/stdc++.h> 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 da; string name; Person(int y,int m,int d,string _s):da(y,m,d),name(_s) { printf("Person "); cout << name; printf(" was born at %d-%d-%d is created. ",da.y,da.m,da.d); } ~Person() { printf("Person "); cout << name; printf(" was born at %d-%d-%d is erased. ",da.y,da.m,da.d); } };
Problem C: 类型可变的类
题面:
main函数：
int main() { Data d1; int i; cin>>i; Data d2(i); double d; cin>>d; Data d3(d); return 0; }
考点：重载
AC代码：
#include <bits/stdc++.h> using namespace std; class Data { public: int flag ; int i; double d; Data():flag(0){printf("A default object is created. ");} Data(int _d):flag(1),i(_d){ printf("An integer object %d is created. ",i); } Data(double _d):flag(2),d(_d){ cout << "A double object "; cout << d ; cout << " is created." << endl; } ~Data() { if(flag==0) { printf("The default object is erased. "); } else if(flag==1) { printf("The integer object %d is erased. ",i); } else if(flag==2) { cout << "The double object "; cout << d ; cout << " is erased." << endl; } } };
Problem D: 学校的构成（I）
题面：
main函数：
int main() { int g; double s; cin>>g>>s; School sch(g, s); cin>>g; Student stu(g); cin>>s; Teacher tea(s); School(g, s); return 0; }
考点：类的组合
AC代码：
include <bits/stdc++.h> using namespace std; class Student { public: int n; Student(int _n):n(_n) { printf("A student grade %d is created. ",n); } ~Student() { printf("A student grade %d is erased. ",n); } }; class Teacher { public: double wage; Teacher(double _d):wage(_d) { printf("A teacher with salary "); cout << wage ; printf(" is created. "); } ~Teacher() { printf("A teacher with salary "); cout << wage ; printf(" is erased. "); } }; class School { public: Student stu; Teacher tea; School(int _g,double _s):stu(_g),tea(_s) { printf("A school is created. "); } ~School() { printf("A school is erased. "); } };
Problem E: 简单类定义
题面：
main函数：
int main() { Test t1; int i; cin>>i; Test t2(i); cout<<"t2 is "<<t2.getMem()<<"."<<endl; cin>>i; t2.setMem(i); cout<<"t2 is "<<t2.getMem()<<"."<<endl; return 0; }
考点：类的使用
AC代码：
#include <bits/stdc++.h> using namespace std; class Test { public: int d; Test(int _d=0):d(_d) { printf("Test %d is created. ",d); } void setMem(int x) { d = x; } int getMem() { return d; } ~Test() { printf("Test %d is erased. ",d); } };
Problem F: 圆的面积
题面：
main函数：
int main() { double radius; cout<<"PI="<<Circle::PI<<endl; const Circle c1(2); cout<<"radius="<<c1.getRadius(); cout<<",area="<<c1.getArea()<<endl; cin>>radius; Circle c2(radius); cout<<"radius="<<c2.getRadius(); cout<<",area="<<c2.getArea()<<endl; return 0; }
考点：类的使用
AC代码：
#include <bits/stdc++.h> using namespace std; class Circle { public: double r; static double PI; Circle(double _r):r(_r) { } double getArea()const { return PI*r*r; } double getRadius()const { return r; } };
Problem G: 新型乘法运算
题面：
main函数：
int main() { Integer M, N; int a, n, m; cin>>a; M.setValue(a); cin>>n; while (n--) { cin>>m; N = M * m; cout<<N.getValue()<<endl; } return 0; }
考点：先求位数，然后乘10的位数方然后再加上原来的数
AC代码：
#include <bits/stdc++.h> using namespace std; class Integer { public: int v; Integer(int _v=0):v(_v){} void setValue(int _v) { v = _v; } int getValue() { return v; } Integer operator *(int d) { int x = 1,k = v; while(k) { //cout << 2 << endl; x*=10; k/=10; } k = 0; for(int i = 0;i<d;i++) k= k*x+v; //cout << k << endl; return Integer(k); } Integer operator =(Integer b) { v = b.v; return *this; } };
Problem H: 高阶多项式（IV）
题面：
main函数：
int main() { int n, i; cin>>n; for (i = 0; i < n; i++) { Equation eq; cin>>eq; cout<<eq; } return 0; }
考点：运算符的重载，输出格式控制
AC代码：
int main() { int n, i; cin>>n; for (i = 0; i < n; i++) { Equation eq; cin>>eq; cout<<eq; } return 0; }
Problem I: 老师的工资
题面：
main函数：
int main() { int N, i, m; char ch; double basis; Teacher *t; cin>>N; for (i = 0; i < N; i++) { cin>>ch>>basis>>m; if (ch == 'h') t = new HighSchoolTeacher(basis, m); else if (ch == 'u') t = new UniversityTeacher(basis, m); cout<<setprecision(2)<<setiosflags(ios::fixed)<<t->getSalary()<<endl; delete t; } return 0; }
考点：类的继承，虚基类
AC代码：
#include <bits/stdc++.h> using namespace std; class Teacher { public: double b; int m; Teacher(double _b,int _m):b(_b),m(_m) { printf("Teacher's constructor. "); } virtual double getSalary()=0; virtual ~Teacher() { printf("Teacher's deconstructor. "); } }; class HighSchoolTeacher:public Teacher { public: HighSchoolTeacher(double _b,int _m):Teacher(_b,_m) { printf("HighSchoolTeacher's constructor. "); } double getSalary() { //cout << b << " " << m << endl; return b+m*100.0; } ~HighSchoolTeacher() { printf("HighSchoolTeacher's deconstructor. "); } }; class UniversityTeacher:public Teacher { public: UniversityTeacher(double _d,int m):Teacher(_d,m) { printf("UniversityTeacher's constructor. "); } double getSalary() { if(m<240) return b + (m-240)*20; else if(m>240) return b+(m-240)*40; } ~UniversityTeacher() { printf("UniversityTeacher's deconstructor. "); } };