第三题，不知道对不对
#include <iostream>
(30316)#include <vector>
using namespace std;
int main(int argc, char const *argv[])
{
int startNumber;
while (cin >> startNumber)
{
int arrA[startNumber + 1] = {0};
int arrB[startNumber + 1] = {0};
arrA[startNumber] = 1;
arrB[startNumber] = 0;
for (int i = startNumber; i >= 0; i--)
{
arrA[i - 1] += arrB[i];
arrA[i - 2] += arrB[i];
arrB[i - 1] += arrA[i];
arrB[i - 2] += arrA[i];
}
cout << arrB[7];
}
return 0;
}
