Leetcode keyboard problem [650] and [651]

4 keyboard

class Solution {
public:
    int maxA(int N) {
        vector<int> dp(N + 1, 0);
        for (int i = 0; i <= N; ++i) {
            dp[i] = i;
            for (int j = 1; j < i - 2; ++j) {
                dp[i] = max(dp[i], dp[j] * (i - j - 1));
            }
        }
        return dp[N];
    }
};
           

2 keyboard

class Solution {
public:
    int minSteps(int n) {
        vector<int> dp(n + 1, 0);
        for (int i = 2; i <= n; ++i) {
            dp[i] = i;
            for (int j = i - 1; j > 1; --j) {
                if (i % j == 0) {
                    dp[i] = min(dp[i], dp[j] + i / j);
                }
            }
        }
        return dp[n];
    }
};