| 3084 | Count Substrings Starting and Ending with Given Character | MathStringCounting | Medium |
| 3085 | Minimum Deletions to Make String K-Special | Hash TableStringGreedy+2 | Medium |
| 3091 | Apply Operations to Make Sum of Array Greater Than or Equal to k | MathGreedyEnumeration | Medium |
| 3092 | Most Frequent IDs | ArrayHash TableHeap (Priority Queue)+1 | Medium |
| 3096 | Minimum Levels to Gain More Points | ArrayPrefix Sum | Medium |
| 3097 | Shortest Subarray With OR at Least K II | ArrayBit ManipulationSliding Window | Medium |
| 3100 | Water Bottles II | MathSimulation | Medium |
| 3101 | Count Alternating Subarrays | ArrayMath | Medium |
| 3106 | Lexicographically Smallest String After Operations With Constraint | StringGreedy | Medium |
| 3107 | Minimum Operations to Make Median of Array Equal to K | ArrayGreedySorting | Medium |
| 3111 | Minimum Rectangles to Cover Points | ArrayGreedySorting | Medium |
| 3112 | Minimum Time to Visit Disappearing Nodes | ArrayGraphHeap (Priority Queue)+1 | Medium |
| 3115 | Maximum Prime Difference | ArrayMathNumber Theory | Medium |
| 3121 | Count the Number of Special Characters II | Hash TableString | Medium |
| 3122 | Minimum Number of Operations to Satisfy Conditions | ArrayDynamic ProgrammingMatrix | Medium |
| 3128 | Right Triangles | ArrayHash TableMath+2 | Medium |
| 3129 | Find All Possible Stable Binary Arrays I | Dynamic ProgrammingPrefix Sum | Medium |
| 3132 | Find the Integer Added to Array II | ArrayTwo PointersSorting+1 | Medium |
| 3133 | Minimum Array End | Bit Manipulation | Medium |
| 3137 | Minimum Number of Operations to Make Word K-Periodic | Hash TableStringCounting | Medium |
| 3138 | Minimum Length of Anagram Concatenation | Hash TableStringCounting | Medium |
| 3143 | Maximum Points Inside the Square | ArrayHash TableString+2 | Medium |
| 3144 | Minimum Substring Partition of Equal Character Frequency | Hash TableStringDynamic Programming+1 | Medium |
| 3147 | Taking Maximum Energy From the Mystic Dungeon | ArrayPrefix Sum | Medium |
| 3148 | Maximum Difference Score in a Grid | ArrayDynamic ProgrammingMatrix | Medium |
| 3152 | Special Array II | ArrayBinary SearchPrefix Sum | Medium |
| 3153 | Sum of Digit Differences of All Pairs | ArrayHash TableMath+1 | Medium |
| 3159 | Find Occurrences of an Element in an Array | ArrayHash Table | Medium |
| 3160 | Find the Number of Distinct Colors Among the Balls | ArrayHash TableSimulation | Medium |
| 3163 | String Compression III | String | Medium |
| 3164 | Find the Number of Good Pairs II | ArrayHash Table | Medium |
| 3169 | Count Days Without Meetings | ArraySorting | Medium |
| 3170 | Lexicographically Minimum String After Removing Stars | Hash TableStringStack+2 | Medium |
| 3175 | Find The First Player to win K Games in a Row | ArraySimulation | Medium |
| 3176 | Find the Maximum Length of a Good Subsequence I | ArrayHash TableDynamic Programming | Medium |
| 3179 | Find the N-th Value After K Seconds | ArrayMathSimulation+2 | Medium |
| 3180 | Maximum Total Reward Using Operations I | ArrayDynamic Programming | Medium |
| 3185 | Count Pairs That Form a Complete Day II | ArrayHash TableCounting | Medium |
| 3186 | Maximum Total Damage With Spell Casting | ArrayHash TableTwo Pointers+4 | Medium |
| 3191 | Minimum Operations to Make Binary Array Elements Equal to One I | ArrayBit ManipulationQueue+2 | Medium |
| 3192 | Minimum Operations to Make Binary Array Elements Equal to One II | ArrayDynamic ProgrammingGreedy | Medium |
| 3195 | Find the Minimum Area to Cover All Ones I | ArrayMatrix | Medium |
| 3196 | Maximize Total Cost of Alternating Subarrays | ArrayDynamic Programming | Medium |
| 3201 | Find the Maximum Length of Valid Subsequence I | ArrayDynamic Programming | Medium |
| 3202 | Find the Maximum Length of Valid Subsequence II | ArrayDynamic Programming | Medium |
| 3207 | Maximum Points After Enemy Battles | ArrayGreedy | Medium |
| 3208 | Alternating Groups II | ArraySliding Window | Medium |
| 3211 | Generate Binary Strings Without Adjacent Zeros | StringBacktrackingBit Manipulation | Medium |
| 3212 | Count Submatrices With Equal Frequency of X and Y | ArrayMatrixPrefix Sum | Medium |
| 3217 | Delete Nodes From Linked List Present in Array | ArrayHash TableLinked List | Medium |