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题目：
Given a nested list of integers, implement an iterator to flatten it.
Each element is either an integer, or a list -- whose elements may also be integers or other lists.
Example 1:
Given the list [[1,1],2,[1,1]],
By calling next repeatedly until hasNext returns false, the order of elements returned by next should be: [1,1,2,1,1].
Example 2:
Given the list [1,[4,[6]]],
By calling next repeatedly until hasNext returns false, the order of elements returned by next should be: [1,4,6].
分析：
代码：
/*** // 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:stack<NestedInteger>record;NestedIterator(vector<NestedInteger> &nestedList) {int size=nestedList.size();for(int i=size-1;i>=0;--i)record.push(nestedList[i]);}int next() {int t=record.top().getInteger();record.pop();return t;}bool hasNext() {while(!record.empty()){NestedInteger ni=record.top();if(ni.isInteger())return true;record.pop();vector<NestedInteger> mylist=ni.getList();int size=mylist.size();for(int i=size-1;i>=0;--i)record.push(mylist[i]);}return false;}
};/*** Your NestedIterator object will be instantiated and called as such:* NestedIterator i(nestedList);* while (i.hasNext()) cout << i.next();*/这篇关于LeetCode *** 341. Flatten Nested List Iterator（审题审题！！）的文章就介绍到这儿，希望我们推荐的文章对编程师们有所帮助！
