Leetcode 887. 鸡蛋掉落

题目

Leetcode 887. 鸡蛋掉落

代码（9.25 首刷看解析）

class Solution {
public:
    unordered_map<int, int> memo;
    int superEggDrop(int K, int N) {
        return dp(K, N);
    }
    int dp(int k, int n) {
        int ans;
        if(!memo.count(n*100+k)) {
            
            if(n == 0) {
                ans = 0;
            } else if(k == 1) {
                ans = n;
            } else {
                int l = 1, r = n;
                while(l+1 < r) {
                    int mid = (l+r)/2;
                    int t1 = dp(k-1, mid-1);    // 碎了
                    int t2 = dp(k, n-mid);  // 没碎
                    if(t1 < t2) {
                        l = mid;
                    } else if(t1 > t2) {
                        r = mid;
                    } else {
                        l = r = mid;
                    }
                }
                ans = 1 + min(max(dp(k-1, l-1), dp(k, n-l)),
                                max(dp(k-1, r-1), dp(k, n-r)));
            }
            memo[n*100+k] = ans;
        }
        return memo[n*100+k];
    }
};