3*N 的矩阵可以由 1*2 的小矩阵组成，问你有多少种情况。  /**/ #include <cstdio> #include <cstring> #include <cmath> #include <cctype> #include <iostream> #include <algorithm> #include <map> #include <set> #include <vector> #include <string> #include <stack> ...