LeetCode Two Sum: Dictionary Hashing Cuts Runtime from 2100ms to 0ms

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A developer tackled LeetCode's classic Two Sum problem, which asks for the indices of two numbers in an array that add up to a given target. The brute-force approach using nested for loops produced a working solution but ran slowly at 2100ms with 13.3MB of memory. A more efficient hashing-based solution using a Python dictionary achieved 0ms runtime while using slightly less memory at 12.9MB. The dictionary method works by storing previously seen values and checking on each iteration whether the required complement already exists. This comparison highlights how choosing the right data structure can dramatically improve algorithmic performance.

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