Master DSA Topics - January, 2026

Practice problems across 75+ categories

All Coding Problems

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# Problem Difficulty Topics
1 01 Matrix Medium
ArrayDynamic ProgrammingBreadth-First Search
2 1-bit and 2-bit Characters Easy
Array
3 132 Pattern Medium
ArrayBinary SearchStack
4 2 Keys Keyboard Medium
MathDynamic Programming
5 24 Game Hard
ArrayMathBacktracking
6 3Sum Medium
ArrayTwo PointersSorting
7 3Sum Closest Medium
ArrayTwo PointersSorting
8 3Sum Smaller Medium
ArrayTwo PointersBinary Search
9 3Sum With Multiplicity Medium
ArrayHash TableTwo Pointers
10 4 Keys Keyboard Medium
MathDynamic Programming
11 4Sum Medium
ArrayTwo PointersSorting
12 4Sum II Medium
ArrayHash Table
13 A Number After a Double Reversal Easy
Math
14 Abbreviating the Product of a Range Hard
Math
15 Accepted Candidates From the Interviews Medium
Database
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public class MyFirstJavaProgram { Edit & Run

   /* This is my first java program.
    * This will print 'Hello, World!' as the output
    */

   public static void main(String []args) {
      System.out.println("Hello, World!"); // prints
   }
}

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