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Topic 6 of 21

Array Problems

From the largest element to Kadane's algorithm, 2Sum, 3Sum and 4Sum, matrix rotation, merging intervals, count inversions and reverse pairs.

40 array problems (16 easy, 19 medium, 5 hard) with LeetCode and GeeksforGeeks links.

Your progress

– / 40 solved

Easy
–/16
Medium
–/19
Hard
–/5
  1. Largest Element in an ArrayEasyGFG
  2. Second Largest Element in an Array Without SortingEasyGFG
  3. Check If the Array Is SortedEasyLeetCodeGFG
  4. Remove Duplicates from Sorted ArrayEasyLeetCodeGFG
  5. Left Rotate an Array by One PlaceEasyLeetCodeGFG
  6. Left Rotate an Array by D PlacesEasyLeetCodeGFG
  7. Move Zeros to EndEasyLeetCodeGFG
  8. Find the UnionMediumGFG
  9. Find Missing Number in an ArrayEasyLeetCodeGFG
  10. Maximum Consecutive OnesEasyLeetCodeGFG
  11. Find the Number That Appears Once, and Other Numbers TwiceMediumLeetCodeGFG
  12. Longest Subarray with Given Sum K (Positives)MediumLeetCodeGFG
  13. Longest Subarray with Sum K (Positives + Negatives)MediumLeetCodeGFG
  14. 2Sum ProblemMediumLeetCodeGFG
  15. Sort an Array of 0's 1's and 2'sMediumLeetCodeGFG
  16. Majority Element (>n/2 Times)EasyLeetCodeGFG
  17. Kadane's Algorithm, Maximum Subarray SumEasyLeetCodeGFG
  18. Print Subarray with Maximum Subarray Sum (Extended Version of Above Problem)MediumGFG
  19. Stock Buy and SellEasyLeetCode
  20. Rearrange the Array in Alternating Positive and Negative ItemsMediumLeetCode
  21. Next PermutationMediumLeetCodeGFG
  22. Leaders in an Array ProblemEasyGFG
  23. Longest Consecutive Sequence in an ArrayMediumLeetCodeGFG
  24. Set Matrix ZerosMediumLeetCodeGFG
  25. Rotate Matrix by 90 DegreesMediumLeetCodeGFG
  26. Print the Matrix in Spiral MannerMediumLeetCodeGFG
  27. Count Subarrays with Given SumEasyLeetCodeGFG
  28. Pascal's TriangleMediumLeetCodeGFG
  29. Majority Element (n/3 Times)MediumLeetCodeGFG
  30. 3-Sum ProblemMediumLeetCodeGFG
  31. 4-Sum ProblemHardLeetCode
  32. Largest Subarray with 0 SumMediumGFG
  33. Count Number of Subarrays with Given XOR KHardGFG
  34. Merge Overlapping SubintervalsMediumLeetCode
  35. Merge Two Sorted Arrays Without Extra SpaceMediumLeetCodeGFG
  36. Find the Repeating and Missing NumberHardLeetCodeGFG
  37. Count InversionsHardLeetCodeGFG
  38. Reverse PairsHardLeetCodeGFG
  39. Maximum Product SubarrayEasyLeetCodeGFG