Comparison [mp]

Micro pattern¶

Description¶

Use local comparisons to determine ordering, movement, search direction, or positional equality.

Problems¶

Compare active front elements¶

Select the smaller available front element when merging sorted sequences.

• Top-down merge sort (DSA)
• Top-down merge sort linked list (DSA)
• Bottom-up merge sort (DSA)
• Bottom-up merge sort linked list (DSA)
• 21. Merge Two Sorted Lists (Top Easy)
• 88. Merge Sorted Array (Top Easy)
• 148. Sort List (Top Hard)

Direct pointers or search boundaries¶

Compare an active value with a target or boundary to choose the next position.

• 15. 3Sum (Top Medium)
• 33. Search in Rotated Sorted Array (Top Medium)
• 162. Find Peak Element (Top Medium)
• 240. Search a 2D Matrix II (Top Medium)
• 11. Container With Most Water (Top Hard)
• 4. Median of Two Sorted Arrays (Top Hard)
• 42. Trapping Rain Water (Top Hard)

Custom ordering¶

Compare composed arrangements when ordinary ordering does not capture the objective.

• 179. Largest Number (Top Hard)

Positional equality¶

Compare structurally related positions while extending a run, path, or symmetric region.

• 5. Longest Palindromic Substring (Top Medium)
• 38. Count and Say (Top Medium)
• 79. Word Search (Top Medium)
• 13. Roman to Integer (Top Easy)
• 839. Similar String Groups (Graph Theory)
• 72. Edit Distance (Dynamic Programming)
• 712. Minimum ASCII Delete Sum for Two Strings (Dynamic Programming)
• 115. Distinct Subsequences (Dynamic Programming)
• 1143. Longest Common Subsequence (Dynamic Programming)
• 1035. Uncrossed Lines (Dynamic Programming)