题目

integer-break

2. 算法

* 直接模拟

* 优化

3. 代码

* 直接模拟

class Solution {
public:
    int integerBreak(int n) {
        if (n == 2 || n == 3) return n - 1;
        int res = 1;
        while (n > 4) {
            res *= 3;
            n -= 3;
        }
        return res * n;
    }
};

* 优化

class Solution {
public:
    int integerBreak(int n) {
        vector<int> dp{0, 0, 1, 2, 4, 6, 9};
        for (int i = 7; i <= n; ++i) {
            dp.push_back(3 * dp[i - 3]);
        }
        return dp[n];
    }
};