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Problems Contests

Practice coding problems

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Practice coding problems

Data structures and algorithms problems in Python and Java. Read any problem for free; sign in to run and submit your code.

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35 problems

ProblemDifficultyTopicsTime

Factorial of a NumberFoundational
Easy10 min

Recursion Fundamentals

Sum of DigitsFoundationalEasy8 min

Recursion Fundamentals

Two SumEasy20 min

Best Time to Buy and Sell StockEasy20 min

Greedy on Sequences

Majority ElementEasy20 min

Move ZeroesEasy20 min

Two Pointers

Squares of a Sorted ArrayEasy20 min

Two Pointers

Third Maximum NumberEasy20 min

Selection Algorithms

Find Pivot IndexEasy20 min

Prefix Sums and Difference Arrays

Find the Maximum Element in an ArrayEasy15 min

Arrays and Strings

Find the Minimum Element in an ArrayEasy15 min

Arrays and Strings

Calculate the Sum of Array ElementsEasy15 min

Arrays and Strings

Find the First Occurrence of a TargetEasy15 min

Arrays and Strings

Reverse an ArrayEasy15 min

Arrays and Strings

Count Even Numbers in an ArrayEasy15 min

Arrays and Strings

Find the Second Largest Distinct ElementEasy15 min

Arrays and Strings

Rotate an Array to the RightEasy15 min

Array Techniques

Move All Zeroes to the EndEasy15 min

Two Pointers

Check Whether an Array Is SortedEasy15 min

Arrays and Strings

Check Whether a Number Is EvenFoundationalEasy15 min

Programming Fundamentals

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