{"id":467,"date":"2025-06-29T20:24:00","date_gmt":"2025-06-29T14:54:00","guid":{"rendered":"https:\/\/codeanddebug.in\/blog\/?p=467"},"modified":"2025-06-29T20:24:01","modified_gmt":"2025-06-29T14:54:01","slug":"sort-colors","status":"publish","type":"post","link":"https:\/\/codeanddebug.in\/blog\/sort-colors\/","title":{"rendered":"Sort Colors | Leetcode 75 | Brute, Better and Optimal"},"content":{"rendered":"\n

LeetCode \u201cSort Colors\u201d<\/strong> (#75) asks you to sort an array that contains only three distinct values\u20140<\/code>, 1<\/code>, and 2<\/code>\u2014so that all 0<\/code>s come first, then all 1<\/code>s, and finally all 2<\/code>s.
The trick: do it entirely in-place<\/strong> and, ideally, in a single pass.<\/p>\n\n\n\n

Input<\/th>Output<\/th><\/tr><\/thead>
[2, 0, 2, 1, 1, 0]<\/code><\/td>[0, 0, 1, 1, 2, 2]<\/code><\/td><\/tr>
[2, 0, 1]<\/code><\/td>[0, 1, 2]<\/code><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

The problem is famously solved by the Dutch National Flag<\/strong> algorithm\u2014but we\u2019ll walk through three escalating solutions to see how you reach that \u201coptimal\u201d idea.<\/p>\n\n\n\n

Here’s the [Problem Link<\/span><\/mark><\/a><\/strong>] to begin with.<\/p>\n\n\n

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