Lintcode：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。

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]

。

python：

class Solution(object):

# @param nestedList a list, each element in the list
# can be a list or integer, for example [1,2,[1,2]]
# @return {int[]} a list of integer
def flatten(self, nestedList):
# Write your code here
if isinstance(nestedList, int):
return [nestedList]
result = []
while len(nestedList) != 0:
temp = nestedList.pop(0)
if isinstance(temp, int):
result.append(temp)
else:
for i in temp[::-1]:
nestedList.insert(0,i)
return result

C++：

/**
* // 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 {
public:
// @param nestedList a list of NestedInteger
// @return a list of integer
vector<int> flatten(vector<NestedInteger> &nestedList) {
// Write your code here
vector<int> result;
for (auto ele:nestedList)
{
if (ele.isInteger())
{
result.push_back(ele.getInteger());
}
else
{
vector<NestedInteger> subList = ele.getList();
vector<int> temp = flatten(subList);
result.insert(result.end(),temp.begin(),temp.end());
}
}
return result;
}
};