백준9095: 1, 2, 3 더하기(Python)
1 -> 1 :1개 2-> 1+1, 2 :2개 3-> (1+1+1), (1+2), (2+1), 3 : 4개 4-> (1+1+1+1), (1+1+2), (1+2+1), (2+1+1), (2+2), (1+3), (3+1) : 7개 점화식으로 표현하면 f(n) = f(n-1)+ f(n-2) + f(n-3) , (n>3인 경우) N = int(input()) def Add(i): if i == 1: return 1 if i == 2: return 2 if i == 3: return 4 return Add(i-1)+Add(i-2)+Add(i-3) for i in range(0,N): i = int(input()) print(Add(i))
2021. 12. 30.
