Leetcode 341. 扁平化嵌套列表迭代器（DAY 143） ---- LeetCode 精选 TOP 面试题

电玩女神 2022-08-29 09:48 230阅读 0赞

### 文章目录 ###

*   *  原题题目
     *  代码实现（首刷自解）

--------------------

## 原题题目 ##

--------------------

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3NTAwNTE2_size_16_color_FFFFFF_t_70]

--------------------

## 代码实现（首刷自解） ##

--------------------

/** * // This is the interface that allows for creating nested lists. * // You should not implement it, or speculate about its implementation * class NestedInteger { * public: * // 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; * * // 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 NestedIterator { 
    public:
        vector<int> ret;
        int pos = 0;
        NestedIterator(vector<NestedInteger> &nestedList) { 
            depthfirstsearch(nestedList);
        }
    
        void depthfirstsearch(vector<NestedInteger> &v)
        { 
            for(int i=0;i<v.size();++i)
            { 
                if(v[i].isInteger())    ret.emplace_back(v[i].getInteger());
                else    depthfirstsearch(v[i].getList());
            }
        }
        
        int next() { 
            return ret[pos++];
        }
        
        bool hasNext() { 
            return pos != ret.size();
        }
    };
    
    /** * Your NestedIterator object will be instantiated and called as such: * NestedIterator i(nestedList); * while (i.hasNext()) cout << i.next(); */

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3NTAwNTE2_size_16_color_FFFFFF_t_70]: /images/20220829/402342c0e07a4bcaa4dddf77d9be28e2.png