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Binary Search — Classic Exact Target
Implement classic binary search to find a target in a sorted array in O(log n) time.
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Classic
10 articles
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Search in Rotated Sorted Array — Half-Sorted Check
Search in a rotated sorted array by identifying which half is sorted and narrowing accordingly.
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Longest Increasing Subsequence — Patience Sort Binary Search
Find the length of LIS in O(n log n) using patience sorting: binary search to maintain a sorted tails array.
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Median of Two Sorted Arrays — Binary Search on Partition
Find the median of two sorted arrays in O(log(min(m,n))) by binary searching for the correct partition point.
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Aggressive Cows — Binary Search on Minimum Distance
Place c cows in stalls to maximize the minimum distance between any two cows using binary search on the answer.
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Guess Number Higher or Lower — Classic Binary Search with API
Find the picked number using binary search with the guess() API that returns -1, 0, or 1.
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Valid Perfect Square — Binary Search or Math
Check if a number is a perfect square in O(log n) using binary search or by exploiting odd-number sum identity.
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Find the Duplicate Number — Binary Search on Count
Find the duplicate in array of n+1 integers in [1,n] using binary search on value with count-of-smaller logic.
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Check If N and Its Double Exist — Binary Search or Hash Set
Check if any element and its double both exist in an array using a hash set or sorting with binary search.
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Trapping Rain Water — Monotonic Stack Horizontal Layer
Calculate trapped rainwater volume using a monotonic stack that computes water in horizontal layers as bars are processed.
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