https://jeanphilogong.github.io/jeanblog/tags/binary-search/Recent content in Binary Search on Jeanphilo BlogHugo -- 0.168.0en-usThu, 13 Aug 2026 00:00:00 +0000https://jeanphilogong.github.io/jeanblog/alg/leetcode/binary-search/74-search-a-2d-matrix/Thu, 13 Aug 2026 00:00:00 +0000https://jeanphilogong.github.io/jeanblog/alg/leetcode/binary-search/74-search-a-2d-matrix/<p>You are given an <code>m x n</code> integer matrix <code>matrix</code> and an integer <code>target</code>. Return <code>True</code> if <code>target</code> is in the matrix; otherwise, return <code>False</code>.</p> <p>The matrix satisfies two conditions:</p> <ul> <li>Every row is sorted in non-decreasing order.</li> <li>The first integer of each row is strictly greater than the last integer of the previous row.</li> </ul> <p>The required time complexity is <code>O(log(m * n))</code>.</p> <p>For example, consider this matrix:</p> <div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-text" data-lang="text"><span style="display:flex;"><span>1 3 5 7 </span></span><span style="display:flex;"><span>10 11 16 20 </span></span><span style="display:flex;"><span>23 30 34 60 </span></span></code></pre></div><ul> <li>When <code>target = 3</code>, return <code>True</code>.</li> <li>When <code>target = 13</code>, return <code>False</code>.</li> </ul> <p>The constraints are:</p>https://jeanphilogong.github.io/jeanblog/alg/leetcode/binary-search/153-find-minimum-in-rotated-sorted-array/Tue, 28 Jul 2026 16:13:57 +0800https://jeanphilogong.github.io/jeanblog/alg/leetcode/binary-search/153-find-minimum-in-rotated-sorted-array/Start from a linear scan, derive a closed minimum-containing interval, and return the rotated array&#39;s minimum in O(log n) time and O(1) auxiliary space.https://jeanphilogong.github.io/jeanblog/alg/leetcode/binary-search/33-search-in-rotated-sorted-array/Tue, 28 Jul 2026 15:40:34 +0800https://jeanphilogong.github.io/jeanblog/alg/leetcode/binary-search/33-search-in-rotated-sorted-array/Derive sorted-half recognition and target-range tests from a linear baseline to search a rotated array in O(log n) time and O(1) auxiliary space.https://jeanphilogong.github.io/jeanblog/alg/leetcode/binary-search/2089-find-target-indices-after-sorting-array/Wed, 18 Mar 2026 13:49:55 +0800https://jeanphilogong.github.io/jeanblog/alg/leetcode/binary-search/2089-find-target-indices-after-sorting-array/Sort the array, locate the target block with lower and upper bounds, and return every target index, with tradeoff analysis, engineering mappings, and runnable implementations in six languages.https://jeanphilogong.github.io/jeanblog/alg/leetcode/binary-search/2529-maximum-count-of-positive-integer-and-negative-integer/Wed, 18 Mar 2026 13:49:55 +0800https://jeanphilogong.github.io/jeanblog/alg/leetcode/binary-search/2529-maximum-count-of-positive-integer-and-negative-integer/Count negatives and positives in a sorted array by locating the boundaries around zero with lower-bound and upper-bound binary search, with engineering mappings and runnable implementations in six languages.https://jeanphilogong.github.io/jeanblog/alg/leetcode/binary-search/34-find-first-and-last-position-of-element-in-sorted-array/Wed, 18 Mar 2026 13:49:55 +0800https://jeanphilogong.github.io/jeanblog/alg/leetcode/binary-search/34-find-first-and-last-position-of-element-in-sorted-array/Start from a linear-scan baseline, derive two half-open binary-search boundaries, and return the complete target range in O(log n) time.https://jeanphilogong.github.io/jeanblog/alg/leetcode/binary-search/35-search-insert-position/Wed, 18 Mar 2026 13:49:55 +0800https://jeanphilogong.github.io/jeanblog/alg/leetcode/binary-search/35-search-insert-position/Find the insertion index of a target in a sorted array with lower-bound binary search in O(log n), with boundary reasoning, engineering mappings, and runnable implementations in six languages.https://jeanphilogong.github.io/jeanblog/alg/leetcode/binary-search/744-find-smallest-letter-greater-than-target/Wed, 18 Mar 2026 13:49:55 +0800https://jeanphilogong.github.io/jeanblog/alg/leetcode/binary-search/744-find-smallest-letter-greater-than-target/Find the smallest character strictly greater than a target in a sorted circular array by using upper-bound binary search and wrap-around logic, with pitfalls, engineering mappings, and runnable implementations in six languages.