Pattern
Backtracking
A compact view of archive entries grouped by recurring technique.
37 entries
37 entries tagged as Backtracking.
17.02.2026
easy401. Binary Watch
All times with count bits set
29.12.2025
medium756. Pyramid Transition Matrix
Can build a pyramid from transitions?
31.08.2025
hard37. Sudoku Solver
Solve sudoku
18.08.2025
hard679. 24 Game
Can a,b,c,d = 24 with ops /+-()
28.07.2025
medium2044. Count Number of Maximum Bitwise-OR Subsets
Subsequencies with max OR
27.06.2025
hard2014. Longest Subsequence Repeated k Times
Longest k-repeating subsequence
12.05.2025
easy2094. Finding 3-Digit Even Numbers
Triple digit even numbers from digits
05.04.2025
easy1863. Sum of All Subset XOR Totals
Sum of all subsets xors
20.02.2025
medium1980. Find Unique Binary String
Binary number not in a set
19.02.2025
medium1415. The k-th Lexicographical String of All Happy Strings of Length n
kth string of abc permutations
18.02.2025
medium2375. Construct Smallest Number From DI String
Smallest number from 1..9 and Inc-Dec pattern
17.02.2025
medium1079. Letter Tile Possibilities
Count uniq sequences from letters
16.02.2025
medium1718. Construct the Lexicographically Largest Valid Sequence
Construct array x = 1..n, a[i] = x, a[i + x] = x
15.02.2025
medium2698. Find the Punishment Number of an Integer
Sum x^2 if it's string partition sum = x
30.11.2024
hard2097. Valid Arrangement of Pairs
Hierholzer algorithm
21.10.2024
medium1593. Split a String Into the Max Number of Unique Substrings
Max count of unique split parts
18.10.2024
medium2044. Count Number of Maximum Bitwise-OR Subsets
Count subsequences with max bitwise or
16.10.2024
medium1405. Longest Happy String
Longest string of a, b, c not repeating 3 times
21.09.2024
medium386. Lexicographical Numbers
Lexicographical ordered numbers 1..n
18.09.2024
medium179. Largest Number
Concatenate nums to largest number
13.08.2024
medium40. Combination Sum II
Unique target sum subsequences
11.08.2024
hard1568. Minimum Number of Days to Disconnect Island
Min changes 1 to 0 to disconnect islands
20.07.2024
medium1605. Find Valid Matrix Given Row and Column Sums
Matrix from rows and cols sums
24.05.2024
hard1255. Maximum Score Words Formed by Letters
Max score of words subset from letters
23.05.2024
medium2597. The Number of Beautiful Subsets
Count subsets without k difference in them
22.05.2024
medium131. Palindrome Partitioning
All palindrome partitions programming
21.05.2024
medium78. Subsets
All subsets
20.05.2024
easy1863. Sum of All Subset XOR Totals
Sum of subsets xors
14.05.2024
medium1219. Path with Maximum Gold
Max one-way path in matrix
10.05.2024
medium786. K-th Smallest Prime Fraction
kth arr[i]/arr[j], i < j, arr[i] < arr[j] search
25.04.2024
medium2370. Longest Ideal Subsequence
Max length of less than k adjacent subsequence programming
14.09.2023
hard332. Reconstruct Itinerary
Smallest lexical order path using all the tickets
05.08.2023
medium95. Unique Binary Search Trees II
All possible Binary Search Trees for 1..n numbers
02.08.2023
medium46. Permutations
List of all numbers permutations
15.07.2023
hard1751. Maximum Number of Events That Can Be Attended II
Max sum of at most k values from non-intersecting array of (from, to, value) items
1.07.2023
medium2305. Fair Distribution of Cookies
Min of the max distributing n cookies to k children
27.06.2023
medium373. Find K Pairs with Smallest Sums
List of increasing sum pairs a[i], b[j] from two sorted lists a, b