lintcode.22 平面列表

平面列表 

 

• 描述
• 笔记
• 数据
• 评测

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。

您在真实的面试中是否遇到过这个题？

Yes

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;
    }
};