| 3343 | Count Number of Balanced Permutations | MathStringDynamic Programming+1 | Hard |
| 3347 | Maximum Frequency of an Element After Performing Operations II | ArrayBinary SearchSliding Window+2 | Hard |
| 3348 | Smallest Divisible Digit Product II | MathStringBacktracking+2 | Hard |
| 3351 | Sum of Good Subsequences | ArrayHash TableDynamic Programming | Hard |
| 3352 | Count K-Reducible Numbers Less Than N | MathStringDynamic Programming+1 | Hard |
| 3357 | Minimize the Maximum Adjacent Element Difference | ArrayBinary SearchGreedy | Hard |
| 3363 | Find the Maximum Number of Fruits Collected | ArrayDynamic ProgrammingMatrix | Hard |
| 3367 | Maximize Sum of Weights after Edge Removals | Dynamic ProgrammingTreeDepth-First Search | Hard |
| 3373 | Maximize the Number of Target Nodes After Connecting Trees II | TreeDepth-First SearchBreadth-First Search | Hard |
| 3374 | First Letter Capitalization II | Database | Hard |
| 3378 | Count Connected Components in LCM Graph | ArrayHash TableMath+2 | Hard |
| 3382 | Maximum Area Rectangle With Point Constraints II | ArrayMathBinary Indexed Tree+3 | Hard |
| 3389 | Minimum Operations to Make Character Frequencies Equal | Hash TableStringDynamic Programming+2 | Hard |
| 3395 | Subsequences with a Unique Middle Mode I | ArrayHash TableMath+1 | Hard |
| 3398 | Smallest Substring With Identical Characters I | ArrayBinary SearchEnumeration | Hard |
| 3399 | Smallest Substring With Identical Characters II | StringBinary Search | Hard |
| 3405 | Count the Number of Arrays with K Matching Adjacent Elements | MathCombinatorics | Hard |
| 3410 | Maximize Subarray Sum After Removing All Occurrences of One Element | ArrayDynamic ProgrammingSegment Tree | Hard |
| 3414 | Maximum Score of Non-overlapping Intervals | ArrayBinary SearchDynamic Programming+1 | Hard |
| 3420 | Count Non-Decreasing Subarrays After K Operations | ArrayStackSegment Tree+4 | Hard |
| 3425 | Longest Special Path | ArrayHash TableTree+2 | Hard |
| 3426 | Manhattan Distances of All Arrangements of Pieces | MathCombinatorics | Hard |
| 3430 | Maximum and Minimum Sums of at Most Size K Subarrays | ArrayMathStack+1 | Hard |
| 3435 | Frequencies of Shortest Supersequences | ArrayStringBit Manipulation+3 | Hard |
| 3441 | Minimum Cost Good Caption | StringDynamic Programming | Hard |
| 3444 | Minimum Increments for Target Multiples in an Array | ArrayMathDynamic Programming+3 | Hard |
| 3445 | Maximum Difference Between Even and Odd Frequency II | StringSliding WindowEnumeration+1 | Hard |
| 3448 | Count Substrings Divisible By Last Digit | StringDynamic Programming | Hard |
| 3449 | Maximize the Minimum Game Score | ArrayBinary SearchGreedy | Hard |
| 3451 | Find Invalid IP Addresses | Database | Hard |
| 3454 | Separate Squares II | ArrayBinary SearchSegment Tree+1 | Hard |
| 3455 | Shortest Matching Substring | Two PointersStringBinary Search+1 | Hard |
| 3459 | Length of Longest V-Shaped Diagonal Segment | ArrayDynamic ProgrammingMemoization+1 | Hard |
| 3463 | Check If Digits Are Equal in String After Operations II | MathStringCombinatorics+1 | Hard |
| 3464 | Maximize the Distance Between Points on a Square | ArrayBinary SearchGreedy | Hard |
| 3470 | Permutations IV | ArrayMathCombinatorics+1 | Hard |
| 3474 | Lexicographically Smallest Generated String | StringGreedyString Matching | Hard |
| 3480 | Maximize Subarrays After Removing One Conflicting Pair | ArraySegment TreeEnumeration+1 | Hard |
| 3482 | Analyze Organization Hierarchy | Database | Hard |
| 3485 | Longest Common Prefix of K Strings After Removal | ArrayStringTrie | Hard |
| 3486 | Longest Special Path II | ArrayHash TableTree+2 | Hard |
| 3490 | Count Beautiful Numbers | Dynamic Programming | Hard |
| 3495 | Minimum Operations to Make Array Elements Zero | ArrayMathBit Manipulation | Hard |
| 3500 | Minimum Cost to Divide Array Into Subarrays | ArrayDynamic ProgrammingPrefix Sum | Hard |
| 3501 | Maximize Active Section with Trade II | ArrayStringBinary Search+1 | Hard |
| 3504 | Longest Palindrome After Substring Concatenation II | Two PointersStringDynamic Programming | Hard |
| 3505 | Minimum Operations to Make Elements Within K Subarrays Equal | ArrayHash TableMath+3 | Hard |
| 3509 | Maximum Product of Subsequences With an Alternating Sum Equal to K | ArrayHash TableDynamic Programming | Hard |
| 3510 | Minimum Pair Removal to Sort Array II | ArrayHash TableLinked List+4 | Hard |
| 3515 | Shortest Path in a Weighted Tree | ArrayTreeDepth-First Search+2 | Hard |