[백준] 2579번 계단 오르기 (파이썬)

https://www.acmicpc.net/problem/2579

n = int(input())
arr = [0]
for _ in range(n):
    arr.append(int(input()))
    
dp = [0]*(n+1)
dp[1] = arr[1]
if n >= 2:
    dp[2] = arr[1] + arr[2]
if n >= 3:
    for i in range(3, n+1):
        dp[i] = max(dp[i-2]+arr[i], dp[i-3]+arr[i-1]+arr[i])

print(dp[n])