364.cpp

/**
 * // This is the interface that allows for creating nested lists.
 * // You should not implement it, or speculate about its implementation
 * class NestedInteger {
 *   public:
 *     // Constructor initializes an empty nested list.
 *     NestedInteger();
 *
 *     // Constructor initializes a single integer.
 *     NestedInteger(int value);
 *
 *     // Return true if this NestedInteger holds a single integer, rather than a nested list.
 *     bool isInteger() const;
 *
 *     // Return the single integer that this NestedInteger holds, if it holds a single integer
 *     // The result is undefined if this NestedInteger holds a nested list
 *     int getInteger() const;
 *
 *     // Set this NestedInteger to hold a single integer.
 *     void setInteger(int value);
 *
 *     // Set this NestedInteger to hold a nested list and adds a nested integer to it.
 *     void add(const NestedInteger &ni);
 *
 *     // Return the nested list that this NestedInteger holds, if it holds a nested list
 *     // The result is undefined if this NestedInteger holds a single integer
 *     const vector<NestedInteger> &getList() const;
 * };
 */
class Solution {
public:
    int maxDepth = 0;
    int sum = 0;
    int productSum = 0;
    void dfs(vector<NestedInteger>& nestedList, int depth) {
        if (nestedList.size() != 0) maxDepth = max(maxDepth, depth);
        for (auto& nested : nestedList) {
            if (nested.isInteger()) {
                int num = nested.getInteger();
                sum += num;
                productSum += depth * num;
            }
            else {
                dfs(nested.getList(), depth + 1);
            }
        }
    }
    int depthSumInverse(vector<NestedInteger>& nestedList) {
        dfs(nestedList, 1);
        return (maxDepth + 1) * sum - productSum;
    }
};