📜 WAYPOINT LESSON
Binary Search on the Answer
⭐⭐⭐ advanced⏳ 30 min read📍 Lesson 183 of 281
When feasibility is monotone in a numeric answer, binary search the answer and verify greedily in O(n).
Searching the answer space
Max-min-distance problems: 'can we place k points with all gaps >= d?' is monotone in d. Binary search d; the check is a linear greedy. The off-by-one traps: gaps EXACTLY d count (>=), and the search bounds. Write the predicate on paper before coding it.
⚡ Now practice
Ready to CodeSynthesis GauntletSubarray-sum-range counting, inversions over sparse values, interval scheduling, and max-min-distance placement.
3 challenges · · ~120 min