Leetcode Solutions Java Python C++
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251. Flatten 2D Vector

Design and implement an iterator to flatten a 2d vector. It should support the following operations: next and hasNext.

 

Example:

Vector2D iterator = new Vector2D([[1,2],[3],[4]]);

iterator.next(); // return 1
iterator.next(); // return 2
iterator.next(); // return 3
iterator.hasNext(); // return true
iterator.hasNext(); // return true
iterator.next(); // return 4
iterator.hasNext(); // return false

 

Notes:

  1. Please remember to RESET your class variables declared in Vector2D, as static/class variables are persisted across multiple test cases. Please see here for more details.
  2. You may assume that next() call will always be valid, that is, there will be at least a next element in the 2d vector when next() is called.

 

Follow up:

As an added challenge, try to code it using only iterators in C++ or iterators in Java.

Difficulty:

Medium

Lock:

Prime

Company:

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Problem Solution

251-Flatten-2D-Vector-

All Problems:

Link to All Problems
All contents and pictures on this website come from the Internet and are updated regularly every week. They are for personal study and research only, and should not be used for commercial purposes. Thank you for your cooperation.