几天前,我在这里问了一个关于Rabbits程序的问题,我设法ALMOST完成了它。问题是当我输入0时,它崩溃并且无法运行。有人可以帮帮我,这是我的任务:
将一对新生兔子(一只雄性,一只雌性)放在田里。兔子能够在一个月大的时候交配,因此在第二个月的月底,每对都会产生两对新的兔子,然后死亡。
注意:在第0个月中,有0对兔子。在第1个月,有1对兔子。
#include <iostream>
using namespace std;
int rabbits (int);
int main ()
{
int month_function, month_while, result_rec, result_while, counter = 0, rab_now, rab_lastmonth = 0, rab_twomonthsago = 1;
cout << "Please enter the month. \n\n";
cin >> month_function;
month_while = month_function;
cout << "\n";
if (month_function % 2 == 0) // if month entered is even, the recursive function will use month - 1 because the total number of rabbits doubles every other month
{
month_function--;
}
result_rec = rabbits (month_function);
while (counter < month_while)
{
if (counter % 2 == 0)
{
rab_now = rab_lastmonth + rab_twomonthsago;
rab_lastmonth = rab_now;
rab_twomonthsago = rab_now;
}
counter++;
result_while = rab_lastmonth;
}
cout << "According to the recursive function, there are " << result_rec << " pairs of rabbits at the end of month " << month_while << "\n\n";
cout << "According to the while loop, there are " << result_while << " pairs of rabbits at the end of month " << month_while << endl;
if (result_rec = result_while)
{
cout << "\n";
cout << "They are equal!" << endl;
}
else
{
cout << "They are not equal!" << endl;
}
return 0;
}
int rabbits (int month_function)
{
if (month_function == 0)
{
return 0;
}
else if (month_function == 1)
{
return 1;
}
else
{
return (rabbits (month_function - 2) + rabbits (month_function - 2));
}
}
最佳答案
您的问题在这里:
if (month_function % 2 == 0) // if month entered is even, the recursive function will use month - 1 because the total number of rabbits doubles every other month
{
month_function--;
}
如果输入0,则计算结果为true,因此
month_function
等于-1
。您(很可能)在逻辑上也有错误。如果为月份功能输入
2
,则将返回0,这是错误的。考虑一下输入2时应该得到什么答案,从那里确定应该很容易。