Every day, I solve one Data Structures & Algorithms problem, write clean code, and share a beginner-friendly guide.
About This Repo.
• 100 days of consistent Java coding.
• Step-by-step explanations for beginners.
• Covers arrays, strings, hashmaps, sorting, recursion & more.
• Both brute-force and optimized approaches when possible.
Progress Tracker
| Day | Topic | Description |
|---|---|---|
| 01 | Count Even & Odd Numbers | Count how many even & odd elements are in an array |
| 02 | Sum & Average | Calculate sum & average of array elements |
| 03 | Pair with Target Sum (Brute Force) | Find pairs of numbers that equal a target |
| 04 | Find Duplicates (Brute Force) | Detect duplicate values in an array |
| 05 | Sort 0s & 1s | Arrange binary array into sorted order |
| 06 | Remove Duplicates (ArrayList) | Remove duplicate values using ArrayList |
| 07 | Largest Subarray with Equal 0s & 1s | Find longest subarray with balanced 0s and 1s |
| 08 | Pair Sum (HashMap) | Optimized target pair finding using HashMap |
| 09 | Find Duplicates (HashMap) | Detect duplicates efficiently with HashMap |
| 10 | Dutch National Flag Algorithm | Sort 0s, 1s, and 2s in O(n) time |
| 11 | Min & Max Finder | Find smallest and largest numbers in array |
| 12 | Reverse an Array | Reverse an Array |
| 13 | Rotate an Array by k positions | Rotate an Array by k positions Using Two For Loop |
| 14 | Move Zeros to End | shift all zeros in an array to the end while keeping the order of other numbers the same. |