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C++ 宠物的生长（虚函数和多态）

萌宠菠菠乐园
2024-11-16 01:48

文章目录一、题目描述二、输入与输出1.输入2.输出三、参考代码

一、题目描述

需要开发一个系统，对宠物的生长状态进行管理。给出下面的基类框架：

class Pet

{ protected:

string name;//姓名

float length;//身长

float weight;//体重

CDate current;//开始记录时间

（日期类CDate包含年、月、日三个私有数据，其他方法根据需要自拟。）

public:

virtual void display(CDate day)=0;//输出目标日期时宠物的身长和体重

}

以Pet为基类，构建出Cat和Dog两个类:

Cat一天身长加0.1，体重加0.2。

Dog一天身长加0.2，体重加0.1。

生成上述类并编写主函数，要求主函数中有一个基类指针Pet *pt，用于测试子类数据。

主函数根据输入的信息，相应建立Cat类对象或Dog类对象，并给出测量日期时宠物的身长和体重。

二、输入与输出

1.输入

第一行为测试次数

第二行是开始记录日期

从第三行起，每个测试用例占一行，每行给出宠物的基本信息：宠物的类型（1为Cat，2为Dog）、名字、身长、体重、最后测量的日期。

3 2019 5 5 1 tony 10 10 2018 12 30 2 jerry 5 6 2019 5 10 1 tom 3 4 2019 6 1 12345

2.输出

要求输出目标日期宠物姓名、身长和体重（结果要求保留小数点后2位）。若测量日期小于开始日期，输出”error”。

error jerry after 5 day: length=6.00,weight=6.50 tom after 27 day: length=5.70,weight=9.40 123

三、参考代码

#include <iostream> #include <vector> #include<string> #include<cmath> #include <memory> #include<iomanip> using namespace std; class date { private:int year, mon, day; public:date(){}void set(int y, int m, int d){year = y;mon = m;day = d;}date(int y, int m, int d){year = y;mon = m;day = d;}friend int days(const date& a, const date& b){const int mons1[12] = { 31,28,31,30,31,30,31,31,30,31,30,31 };const int mons2[12] = { 31,29,31,30,31,30,31,31,30,31,30,31 };int ad = a.year * 10000 + a.mon * 1000 + a.day;int bd = b.year * 10000 + b.mon * 1000 + b.day;if (ad > bd){return 0;}else{ad = 0;bd = 0;if (a.year % 400 == 0 || (a.year % 4 == 0 && a.year % 100 != 0)){for (int i = 0; i < a.mon-1; i++){ad += mons2[i];}for (int i = 0; i < a.mon-1; i++){bd += mons2[i];}ad += a.day;bd += b.day;return bd - ad;}else{for (int i = 0; i < a.mon-1; i++){ad += mons1[i];}for (int i = 0; i < b.mon-1; i++){bd += mons1[i];}ad += a.day;bd += b.day;return bd - ad;}}} }; class pet { protected:string name;float len;float wei;date now; public:pet(string n, float l, float w, date n1){name = n;len = l;wei = w;now = n1;}virtual void display(date day) = 0; }; class cat :public pet { public:cat(string n, float l, float w, date n1):pet(n,l,w,n1){}void display(date ago){int lon = days(ago, now);if (lon){cout << name << " after " << lon << " day: length=" << fixed << setprecision(2) << len+lon*0.1 << ",weight=" << fixed << setprecision(2) << wei+lon*0.2 << endl;}else{cout << "error" << endl;}} }; class dog :public pet { public:dog(string n, float l, float w, date n1) :pet(n, l, w, n1) {}void display(date ago){int lon = days(ago, now);if (lon){cout << name << " after " << lon << " day: length=" << fixed << setprecision(2) << len + lon * 0.2 << ",weight=" << fixed << setprecision(2) << wei + lon * 0.1 << endl;}else{cout << "error" << endl;}} }; int main() {int sum;cin >> sum;int y, m, d;string n;int len, wei;cin >> y >> m >> d;date ago(y, m, d);int id;pet* pt;while (sum--){cin >> id;cin >> n >> len >> wei;cin >> y >> m >> d;date now(y, m, d);if (id == 1){pt = new cat (n, len, wei, now);pt->display(ago);}else{pt=new dog(n, len, wei, now);pt->display(ago);}} }

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