time O(n)
space O(n)
N5
N/A
[0]
[1]
[2]
[3]
[4]
[5]
Initialize DP array of size 6.
Pseudocode
Pseudocode
1function climbStairs(n):
2 if n <= 2: return n
3 dp = array of size n + 1
4 dp[1] = 1
5 dp[2] = 2
6 for i = 3 to n:
7 dp[i] = dp[i-1] + dp[i-2]
8 return dp[n]