Problem 502. Would Homer Like It?

Given a matrix of ones and zeros, you must determine if there are any doughnuts present (would Homer Simpson like it?). A doughnut is a 4-connected region of ones completely enclosing a 4-connected region of zeros. You can assume that any regions of ones are either blobs (or genus 0) or doughnuts (genus 1). Thus if you find any hole in a region of ones, it is a doughnut. Also, there are no nested doughnuts.
Return true if any doughnuts are present, otherwise false.
Examples:
This is a doughnut:
1 1 1
1 0 1
1 1 1
Here is another doughnut:
0 0 0 1 1 1
0 1 1 1 0 1
0 0 1 0 0 1
0 0 1 1 1 1
This is not a doughnut:
0 1 0
1 0 1
0 1 0
because the ones are not 4-connected and so can't surround anything.
Solve

Solution Stats

35.0% Correct | 65.0% Incorrect
Last Solution submitted on Nov 28, 2023

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