B.记录Cat类的个体数目
Time Limit: 1000 MS Memory Limit: 32768 K
Total Submit: 22 (17 users) Total Accepted: 12 (12 users) Special Judge: No
Description

定义一个Cat类，拥有静态数据成员HowManyCats，记录Cat的个体数目；静态成员函数GetHowMany（），存取HowManyCats。设计程序测试这个类。

Input

输入整数n，n代表最大的Cat数量。

Output
分行显示HowManyCats值的变化过程。从1..n及从n-1..0的过程。
Sample Input

5
Sample Output

 

There are 1 cats alive!

  There are 2 cats alive!

  There are 3 cats alive!

  There are 4 cats alive!

  There are 5 cats alive!

  There are 4 cats alive!

  There are 3 cats alive!

  There are 2 cats alive!

  There are 1 cats alive!

  There are 0 cats alive!

#include<iostream>
using namespace std;
class cat
{
    public: void getHowMany(int a);
    static int HowManyCats;
};
void cat::getHowMany(int a)
{
    cout<<"There are "<<a<<" cats alive!"<<endl;
}
int cat::HowManyCats=0;
int main()
{
    cat cat1;
    int n;
    cin>>n;
    while(cat1.HowManyCats<n)
    {
        cat1.HowManyCats++;
        cat1.getHowMany(cat1.HowManyCats);
    }
    while(cat1.HowManyCats>0)
    {
        cat1.HowManyCats--;
        cat1.getHowMany(cat1.HowManyCats);
    }
}