题目链接:https://leetcode-cn.com/problems/flatten-nested-list-iterator/
这个题目不难,就是像树的深度遍历,就是题目有点难理解。
/**
* // 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:
queue<int> q;
NestedIterator(vector<NestedInteger> &nestedList) {
dfs(nestedList,q);
}
void dfs(vector<NestedInteger> &nestedList,queue<int> &q){
for(auto x:nestedList){
if(x.isInteger()){
q.push(x.getInteger());
}else{
dfs(x.getList(),q);
}
}
}
int next() {
int result=q.front();
q.pop();
return result;
}
bool hasNext() {
return !q.empty();
}
};
/**
* Your NestedIterator object will be instantiated and called as such:
* NestedIterator i(nestedList);
* while (i.hasNext()) cout << i.next();
*/