lintcode.22 平面列表
平面列表
给定一个列表,该列表中的每个要素要么是个列表,要么是整数。将其变成一个只包含整数的简单列表。
注意事项
如果给定的列表中的要素本身也是一个列表,那么它也可以包含列表。
样例
给定 [1,2,[1,2]]
,返回 [1,2,1,2]
。
给定
[4,[3,[2,[1]]]]
,返回 [4,3,2,1]
/** * // 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 Solution { vector<int> res; public: // @param nestedList a list of NestedInteger // @return a list of integer vector<int> flatten(const vector<NestedInteger> &nestedList) { // Write your code here int size = nestedList.size(); for( int i = 0 ; i < size ; i++ ){ if(nestedList[i].isInteger() ){ res.push_back(nestedList[i].getInteger() ); } else{ flatten(nestedList[i].getList()); } } return res; } };