How should I practice Format a Centered Pagination Bar?

Start by reading the full statement, solve the visible examples, then compare the pattern against related Mixpanel phone screen problems in FastPrep.

Is Format a Centered Pagination Bar associated with Mixpanel?

FastPrep tags this as a Mixpanel phone screen coding practice problem when the problem catalog has that company and stage context.

Problem · Simulation

Format a Centered Pagination Bar

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● Medium

MixpanelFULLTIMEPHONE SCREEN

Problem statement

Format the state of a pagination navigation bar.

The result is a space-separated string containing page numbers and, when pages are hidden, .... Surround currentPage with square brackets. The bar must obey these rules:

Show exactly min(totalPages, maxVisiblePages) page-number tokens. Ellipsis tokens do not count as page numbers.
Always show pages 1 and totalPages.
If not all pages fit, show one consecutive window of the remaining page numbers. Center currentPage in that window when possible; otherwise shift the window toward the nearer boundary.
If the interior window has an even number of slots and either centered placement would fit, place currentPage in the left-middle slot so one more page appears to its right.
Insert one ... token between any two shown page numbers that are not consecutive.

Return the formatted navigation bar.

Function

paginate(currentPage: int, totalPages: int, maxVisiblePages: int) → String

Examples

Example 1

currentPage = 1totalPages = 30maxVisiblePages = 11return = "[1] 2 3 4 5 6 7 8 9 10 ... 30"

The nine interior slots shift to the beginning, so pages 2 through 10 are shown.

Example 2

currentPage = 5totalPages = 30maxVisiblePages = 11return = "1 2 3 4 [5] 6 7 8 9 10 ... 30"

The centered ideal would begin before the interior boundary, so the window remains at pages 2 through 10.

Example 3

currentPage = 10totalPages = 30maxVisiblePages = 11return = "1 ... 6 7 8 9 [10] 11 12 13 14 ... 30"

The selected page is centered in the nine-page interior window from 6 through 14.

Example 4

currentPage = 24totalPages = 30maxVisiblePages = 11return = "1 ... 20 21 22 23 [24] 25 26 27 28 ... 30"

The selected page is centered in the interior window from 20 through 28.

Example 5

currentPage = 30totalPages = 30maxVisiblePages = 11return = "1 ... 21 22 23 24 25 26 27 28 29 [30]"

The interior window shifts to its latest possible position so the selected last page remains visible.

Example 6

currentPage = 3totalPages = 5maxVisiblePages = 11return = "1 2 [3] 4 5"

All five pages fit, so the result contains no ellipsis.

Constraints

1 <= totalPages <= 10^9.
1 <= currentPage <= totalPages.
3 <= maxVisiblePages <= 101.