https://leetcode.com/problems/sum-of-all-subset-xor-totals/description/

Sum of subsets xors #easy #dfs #backtracking

https://leetcode.com/problems/the-number-of-beautiful-subsets/description/

Count subsets without k difference in them #medium #dfs #backtracking

https://leetcode.com/problems/maximum-score-words-formed-by-letters/description/

Max score of words subset from letters #hard #backtracking #dfs

https://leetcode.com/problems/combination-sum-ii/description/

Unique target sum subsequencies #medium #backtracking

https://leetcode.com/problems/count-number-of-maximum-bitwise-or-subsets/description/


Count subsequences with max bitwise or #medium #backtracking

https://leetcode.com/problems/find-the-punishment-number-of-an-integer/description/


Sum x^2 if it's string partition sum = x #medium #backtracking

https://leetcode.com/problems/construct-the-lexicographically-largest-valid-sequence/description/


Construct array x = 1..n, a[i] = x, a[i + x] = x #medium #backtracking

https://leetcode.com/problems/letter-tile-possibilities/description/


Count uniq sequences from letters #medium #backtracking

https://leetcode.com/problems/the-k-th-lexicographical-string-of-all-happy-strings-of-length-n/description/


k`th string of `abc permutations #medium #backtracking

https://leetcode.com/problems/find-unique-binary-string/description/

Binary number not in a set #medium #backtracking

# 27.06.2025
[2014. Longest Subsequence Repeated k Times](https://leetcode.com/problems/longest-subsequence-repeated-k-times/description/) hard


Longest k-repeating subsequence #hard #backtracking

# 18.08.2025
[679. 24 Game](https://leetcode.com/problems/24-game/description) hard

Can a,b,c,d = 24 with ops */+-() #hard #backtracking #math