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; }