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Hash Map problems - the most common interview pattern?

Simran JainSimran Jain
8 months ago
10

I feel like HashMap is the single most useful data structure in interviews. It's the answer to like 30% of all problems:

  • Two Sum → HashMap
  • Group Anagrams → HashMap
  • Longest substring without repeating → HashMap + sliding window
  • Top K frequent elements → HashMap + heap
  • Subarray sum equals K → HashMap (prefix sum)

If you're short on time and can only master one data structure, make it HashMap. Change my mind.

hashmappatternsinterview-prepdsa

Comments (2)

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Lakshay Desai
Lakshay Desai7 months ago(edited)

Honestly, I struggled with understanding how to efficiently use HashMaps initially. Any tips for getting comfortable with them, especially for interview scenarios?

Priyanka Chakraborty
Priyanka Chakraborty8 months ago

Totally agree! HashMap is definitely versatile, but sometimes I feel like it's overused. Like, there might be better solutions for certain problems if we think outside the hashmap box.