Replay the ticket board

EasyArraysStacks

A tasting counter records ticket edits in order. A positive integer adds that ticket number to the end of the board. A zero undoes the most recent ticket still on the board; if the board is empty, the zero does nothing. Return the final ticket numbers from oldest to newest. Repeated numbers represent separate tickets, and an undo does not restore an earlier undone ticket.

Example 1

INPUT[8,3,0,5]OUTPUT[8,5]

Ticket 3 is undone. Ticket 8 remains before the newly added ticket 5.

Example 2

INPUT[0,4,0,0]OUTPUT[]

The first zero has nothing to undo. The next removes ticket 4, and the last again does nothing.

Keep in mind

0 <= events.length <= 20,000
Each event is an integer from 0 to 1,000,000.
Zero is an undo command, never a ticket number.

/** @returns {number[]} */
function solve(events) {
  // Return the result described above.
}

/** @returns {number[]} */
function solve(events) {
  // Return the result described above.
}

INPUT[8,3,0,5]

EXPECTED OUTPUT[8,5]

Public samples only. These checks do not award ranked points.

AFTER THE SOLVE

How the solution works.

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Replay the ticket board

Example 1

Example 2

Keep in mind

How the solution works.

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