DSA
Extended Boyer-Moore Voting — find all elements appearing more than ⌊n/3⌋ times. Time O(n), Space O(1).
Keep each unique element at most twice in-place. Optimal — Time O(n), Space O(1).
Covers: Brute Force, Extra Array, Optimal (Reverse). Optimal — Time O(n), Space O(1).
Covers: Brute Force, Optimal Prefix Sum. Best — Time O(n), Space O(n).
Simulation approach — transpose + row-reverse. Time O(n²), Space O(1).
Covers: Brute Force, Better, Optimal. Optimal — Time O(nlogn), Space O(t).
Simulation approach.
Covers: Set, Greedy. Optimal — Time O(m*n), Space O(1).
Covers: Extra Space (Naive), Two Pointers from End (Optim…, Gap Method (Shell Sort idea). Optimal — Space O(m + n).
Covers: Brute Force, Optimal. Optimal — Time O(n), Space O(n).
Arrays. Time O(n), Space O(1).
Covers: Brute Force, Better, Optimal. Optimal — Time O(n), Space O(n).
Covers: Brute Force, Optimal (Only Positives), Optimal Approach (Handling P…. Optimal — Time O(n), Space O(n).
Boyer-Moore Voting Algorithm approach. Optimal — Time O(n), Space O(1).
Covers: Brute Force, Optimal. Optimal — Time O(m*n), Space O(1).
Optimal approach. Optimal — Time O(n), Space O(1).
Covers: Brute Force, Kadane's Algo. Optimal — Time O(n), Space O(1).
Covers: Sorting, Linear Scan. Optimal — Time O(n), Space O(1).
Covers: Brute Force, Sliding Window. Optimal — Time O(n), Space O(1).
5 approaches incl. Brute Force, Better, II, and more. Optimal — Time O(n), Space O(1).
Arrays problem — solution with code and analysis.
Covers: Brute Force, Two pointer. Optimal — Time O(n), Space O(1).
Covers: Brute Force, Optimal. Optimal — Time O(n), Space O(1).
Covers: Brute Force, Merge Sort (Optimal).
nCr Formula approach. Optimal — Time O(c), Space O(1).
optimal approach. Optimal — Time O(n), Space O(1).
Covers: Brute Force, Better, Optimal. Optimal — Time O(log(n * m), Space O(1).
Covers: Brute Force, Better, Optimal. Optimal — Time O(n), Space O(1).
Covers: Brute Force, Better.
Covers: HashMap, Optimal. Optimal — Time O(nlogn), Space O(n).
Covers: sorting Based, Better, Union Find. Optimal — Time O(n), Space O(n).
Arrays. Time O(n), Space O(n).
Covers: Brute Force, prefix Sum, Prefix Sum - Space Optimizat…. Optimal — Time O(n), Space O(1).
Covers: brute Force, Two pointer. Optimal — Time O(n), Space O(1).
Covers: Brute Force, Sorting, HashSet. Optimal — Time O(n), Space O(n).
Covers: Brute Force, Optimal, Working. Optimal — Time O(n), Space O(n).
Covers: Brute Force, Better. Optimal — Time O(n^2), Space O(1).
Covers: Brute Force, Binary Search. Optimal — Time O(log n), Space O(1).
Arrays. Time O(nlogn + mlogm), Space O(1).
Prefix Sum approach.
Covers: Brute Force, Two Pointer. Optimal — Time O(n), Space O(1).
Covers: Brute Force, Segment Reversal. Optimal — Time O(n), Space O(1).
Covers: Brute Force, optimal. Optimal — Time O(m*n), Space O(1).
Covers: Brute Force: Linear Search, Binary Search. Optimal — Time O(log n), Space O(1).
Covers: Brute Force: hashmap, XOR. Optimal — Time O(n), Space O(1).
Covers: Brute Force: Sorting, Store freq of 0s, 1s and 2s, Dutch National Flag Algo. Optimal — Time O(n), Space O(1).
Covers: Brute Force, Prefix Sum, Optimal Single-Pass. Best — Time O(n), Space O(n).
Arrays. Time O(h × w), Space O(h × w).
Covers: Brute Force: hashset, Optimal. Optimal — Time O(n + m), Space O(n + m).
Covers: Brute Force, Better. Optimal — Time O(n), Space O(1).
Covers: Recursive, Memoized. Optimal — Time O(n), Space O(n).
Binary Trees. Time O(n), Space O(n).
4 approaches incl. Brute Force, Better, Maths, and more. Optimal — Time O(n), Space O(1).
Graphs. Time O(V^2).
Covers: Greedy, DP. Optimal — Time O(n), Space O(1).
Covers: Linear scan, No extra Space. Optimal — Time O(n), Space O(1).
Intervals problem — solution with code and analysis.
Covers: Sweep line algorithm (or tim…, Min Heap (Priority Queue), Two Sorted Arrays (Two Point…. Optimal — Time O(n log n), Space O(n).
Intervals. Time O(N * logN), Space O(N).
Greedy approach. Optimal — Time O(N * logN), Space O(N).
4 approaches incl. Brute Force: Linear Iteratio…, Better: Binary Search, Alternate Approach: O(nlogn), and more. Optimal — Time O(log n), Space O(1).