4294 Problem A求n!(ni) [1*+]递归算法设计-递归分治1125764295 Problem B斐波那契数列(递归)算法设计-递归分治1142284162 Problem C数塔算法设计-动态规划竞赛-低年级组1014164296 Problem D第k小整数算法设计-递归分治1042894297 Problem E子网掩码算法设计-模拟90203