DDOING

Record my study

My code

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class Solution:
    memo = {}
    def climbStairs(self, n: int) -> int:
        if n == 2:
            return 2
        elif n == 1:
            return 1

        if n not in Solution.memo:
            Solution.memo[n] = Solution.climbStairs(self,n - 1) + Solution.climbStairs(self,n - 2)

        return Solution.memo[n]

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Runtime : 40ms (beats 61.37%)   
Memory : 16.39MB (beats 27.66%)

Bottom - up

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class Solution:
    memo = {0: 1, 1: 1}
    def climbStairs(self, n: int) -> int:

        for i in range(2,n + 1):
            Solution.memo[i] = Solution.memo[i - 1] + Solution.memo[i - 2]

        return Solution.memo[n]

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Runtime : 40ms (beats 61.37%)   
Memory : 16.35MB (Beats 27.66%)

참고