Solved # Title Solution Difficulty 0004 Median of Two Sorted Arrays Java Hard 0015 3sum Java Medium 0033 Search in Rotated Sorted Array Java Medium 0039 Combination Sum Java Medium 0042 Trapping Rain Water Java Hard 0046 Permutations Java Medium 0054 Spiral Matrix Java Medium 0057 Insert Interval Java Medium 0075 Sort Colors Java Medium 0076 Minimum Window Substring Java Hard 0078 Subsets Java Medium 0084 Largest Rectangle in Histogram Java Hard 0098 Validate Binary Search Tree Java Medium 0127 Word ladder Java Hard 0133 Clone Graph Java Medium 0139 Word Break Java Medium 0150 Evaluate reverse polish notation Java Medium 0155 Min Stack Java Medium 0200 Number of Islands Java Medium 0207 Course Schedule Java Medium 0208 Implement Trie (Prefix Tree) Java Medium 0238 Product of Array Except Self Java Medium 0322 Coin Change Java Medium 0329 Longest Increasing Path in a Matrix Java Hard 0416 Partition Equal Subset Sum Java Medium 0542 01 Matrix Java Medium 0576 Out of Boundary Paths Java Medium 0895 Maximum Frequency Stack Java Hard 0981 Time Based Key-Value Store Java Medium 0994 Rotting Oranges Java Medium 1235 Maximum Profit in Job Scheduling Java Hard 2830 Maximize the Profit as the Salesman Java Medium