312.cpp

class Solution {
public:
    int maxCoins(vector<int>& nums) {
        int n = nums.size();
        nums.insert(nums.begin(), 1);
        nums.push_back(1);
        vector<vector<int>> dp(n + 2, vector<int>(n + 2, 0));
        for (int len = 1; len <= n; ++len) {
            for (int i = 1, j = i + len - 1; j <= n; ++i, ++j) {
                if (i == j) dp[i][j] = nums[i - 1] * nums[i] * nums[i + 1];
                else {
                    for (int k = i; k <= j; ++k) {
                        dp[i][j] = max(dp[i][j], nums[i - 1] * nums[k] * nums[j + 1] + dp[i][k - 1] + dp[k + 1][j]);
                    }
                }
            }
        }
        return dp[1][n];
    }
};