| 151 | Reverse Words in a String | Two PointersString | Medium |
| 152 | Maximum Product Subarray | ArrayDynamic Programming | Medium |
| 153 | Find Minimum in Rotated Sorted Array | ArrayBinary Search | Medium |
| 154 | Find Minimum in Rotated Sorted Array II | ArrayBinary Search | Hard |
| 155 | Min Stack | StackDesign | Medium |
| 160 | Intersection of Two Linked Lists | Hash TableLinked ListTwo Pointers | Easy |
| 162 | Find Peak Element | ArrayBinary Search | Medium |
| 164 | Maximum Gap | ArraySortingBucket Sort+1 | Medium |
| 165 | Compare Version Numbers | Two PointersString | Medium |
| 166 | Fraction to Recurring Decimal | Hash TableMathString | Medium |
| 167 | Two Sum II - Input Array Is Sorted | ArrayTwo PointersBinary Search | Medium |
| 168 | Excel Sheet Column Title | MathString | Easy |
| 169 | Majority Element | ArrayHash TableDivide and Conquer+2 | Easy |
| 171 | Excel Sheet Column Number | MathString | Easy |
| 172 | Factorial Trailing Zeroes | Math | Medium |
| 173 | Binary Search Tree Iterator | StackTreeDesign+3 | Medium |
| 174 | Dungeon Game | ArrayDynamic ProgrammingMatrix | Hard |
| 175 | Combine Two Tables | Database | Easy |
| 176 | Second Highest Salary | Database | Medium |
| 177 | Nth Highest Salary | Database | Medium |
| 178 | Rank Scores | Database | Medium |
| 179 | Largest Number | ArrayStringGreedy+1 | Medium |
| 180 | Consecutive Numbers | Database | Medium |
| 181 | Employees Earning More Than Their Managers | Database | Easy |
| 182 | Duplicate Emails | Database | Easy |
| 183 | Customers Who Never Order | Database | Easy |
| 184 | Department Highest Salary | Database | Medium |
| 185 | Department Top Three Salaries | Database | Hard |
| 187 | Repeated DNA Sequences | Hash TableStringBit Manipulation+3 | Medium |
| 188 | Best Time to Buy and Sell Stock IV | ArrayDynamic Programming | Hard |
| 189 | Rotate Array | ArrayMathTwo Pointers | Medium |
| 190 | Reverse Bits | Divide and ConquerBit Manipulation | Easy |
| 191 | Number of 1 Bits | Divide and ConquerBit Manipulation | Easy |
| 192 | Word Frequency | Shell | Medium |
| 193 | Valid Phone Numbers | Shell | Easy |
| 194 | Transpose File | Shell | Medium |
| 195 | Tenth Line | Shell | Easy |
| 196 | Delete Duplicate Emails | Database | Easy |
| 197 | Rising Temperature | Database | Easy |
| 198 | House Robber | ArrayDynamic Programming | Medium |
| 199 | Binary Tree Right Side View | TreeDepth-First SearchBreadth-First Search+1 | Medium |
| 200 | Number of Islands | ArrayDepth-First SearchBreadth-First Search+2 | Medium |
| 201 | Bitwise AND of Numbers Range | Bit Manipulation | Medium |
| 202 | Happy Number | Hash TableMathTwo Pointers | Easy |
| 203 | Remove Linked List Elements | Linked ListRecursion | Easy |
| 204 | Count Primes | ArrayMathEnumeration+1 | Medium |
| 205 | Isomorphic Strings | Hash TableString | Easy |
| 206 | Reverse Linked List | Linked ListRecursion | Easy |
| 207 | Course Schedule | Depth-First SearchBreadth-First SearchGraph+1 | Medium |
| 208 | Implement Trie (Prefix Tree) | Hash TableStringDesign+1 | Medium |