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Two Sum

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Given a list of numbers nums and a number target, return the indices of the two numbers that add up to target. Each input has exactly one answer, and you can't use the same element twice.

two_sum([2, 7, 11, 15], 9) → [0, 1] because 2 + 7 = 9.

🧪 Practice

Write your solution, then press Run tests. Explain your approach out loud as you go.

def two_sum(nums, target):
    pass

Output appears here. Press Run or Ctrl/⌘ + Enter.

Try it first. Struggling for a few minutes is how it sticks.