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Topic: Combinatorics

47 problems
TitleStatusDifficulty
Unique Paths—Medium
Poor Pigs—Hard
Number of Music Playlists—Hard
Ugly Number III—Medium
Count All Valid Pickup and Delivery Options—Hard
Probability of a Two Boxes Having The Same Number of Distinct Balls—Hard
Number of Ways to Reorder Array to Get Same BST—Hard
Number of Sets of K Non-Overlapping Line Segments—Medium
Count Sorted Vowel Strings—Medium
Kth Smallest Instructions—Hard
Count Ways to Make Array With Productread—Hard
Minimum Number of Operations to Make String Sorted—Hard
Sum of All Subset XOR Totals—Easy
Number of Ways to Rearrange Sticks With K Sticks Visible—Hard
Count Ways to Build Rooms in an Ant Colony—Hard
Vowels of All Substrings—Medium
Find Triangular Sum of an Array—Medium
Count the Number of Ideal Arrays—Hard
Number of Ways to Reach a Position After Exactly k Steps—Medium
Count Anagrams—Hard
The Number of Beautiful Subsetsread—Medium
Count K-Subsequences of a String With Maximum Beautyread—Hard
Distribute Candies Among Children I—Easy
Distribute Candies Among Children II—Medium
Number of Strings Which Can Be Rearranged to Contain Substring—Medium
Count the Number of Infection Sequences—Hard
Count the Number of Good Partitions—Hard
Kth Smallest Amount With Single Denomination Combinationread—Hard
Right Triangles—Medium
Find Number of Ways to Reach the K-th Stair—Hard
Find the N-th Value After K Seconds—Medium
Find the Count of Monotonic Pairs I—Hard
Find the Count of Monotonic Pairs II—Hard
Find the Count of Good Integers—Hard
Sorted GCD Pair Queries—Hard
Find the Number of Possible Ways for an Eventread—Hard
Count Number of Balanced Permutations—Hard
Count K-Reducible Numbers Less Than Nread—Hard
Subsequences with a Unique Middle Mode Iread—Hard
Count the Number of Arrays with K Matching Adjacent Elements—Hard
Manhattan Distances of All Arrangements of Pieces—Hard
Maximum and Minimum Sums of at Most Size K Subsequences—Medium
Check If Digits Are Equal in String After Operations I—Easy
Check If Digits Are Equal in String After Operations II—Hard
Permutations IV—Hard
Smallest Palindromic Rearrangement II—Hard
Find Sum of Array Product of Magical Sequencesread—Hard