2026/03/19

[LeetCode] 70 Climbing Stairs 

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class Solution {
public:
  static constexpr int SIZE = 46;
  int cache[SIZE];
  int dp(int x) {
    if (cache[x])
      return cache[x];
    if (x <= 1) {
      cache[x] = dp(x - 1);
      return cache[x];
    }
    cache[x] = dp(x - 1) + dp(x - 2);
    return cache[x];
  }

  int climbStairs(int n) {
    std::fill(std::begin(cache), std::end(cache), 0);
    cache[0] = 1;
    return dp(n);
  }
};
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