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Description

Write an iterator that iterates through a run-length encoded sequence.

The iterator is initialized by RLEIterator(int[] A), where A is a run-length encoding of some sequence.  More specifically, for all even iA[i] tells us the number of times that the non-negative integer value A[i+1] is repeated in the sequence.

The iterator supports one function: next(int n), which exhausts the next n elements (n >= 1) and returns the last element exhausted in this way.  If there is no element left to exhaust, next returns -1 instead.

For example, we start with A = [3,8,0,9,2,5], which is a run-length encoding of the sequence [8,8,8,5,5].  This is because the sequence can be read as "three eights, zero nines, two fives".

 

Example 1:

Input: ["RLEIterator","next","next","next","next"], [[[3,8,0,9,2,5]],[2],[1],[1],[2]]

Output: [null,8,8,5,-1]

Explanation: 

RLEIterator is initialized with RLEIterator([3,8,0,9,2,5]).

This maps to the sequence [8,8,8,5,5].

RLEIterator.next is then called 4 times:



.next(2) exhausts 2 terms of the sequence, returning 8.  The remaining sequence is now [8, 5, 5].



.next(1) exhausts 1 term of the sequence, returning 8.  The remaining sequence is now [5, 5].



.next(1) exhausts 1 term of the sequence, returning 5.  The remaining sequence is now [5].



.next(2) exhausts 2 terms, returning -1.  This is because the first term exhausted was 5,

but the second term did not exist.  Since the last term exhausted does not exist, we return -1.



Note:

    <li><code>0 &lt;= A.length &lt;= 1000</code></li>
    
    <li><code>A.length</code>&nbsp;is an even integer.</li>
    
    <li><code>0 &lt;= A[i] &lt;= 10^9</code></li>
    
    <li>There are at most <code>1000</code> calls to <code>RLEIterator.next(int n)</code> per test case.</li>
    
    <li>Each call to&nbsp;<code>RLEIterator.next(int n)</code>&nbsp;will have <code>1 &lt;= n &lt;= 10^9</code>.</li>
    

Solutions

Python3

Java

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