Two Sum

Difficulty: Easy · Topic: Arrays & strings

Given an array of integers nums and an integer target, return the indices of the two numbers that add up to target.

You may assume that each input has exactly one solution, and you may not use the same element twice. Return the indices in increasing order.

Examples

two_sum([2,7,11,15], 9)
→ [0,1]

nums[0] + nums[1] = 2 + 7 = 9.

two_sum([3,2,4], 6)
→ [1,2]

nums[1] + nums[2] = 2 + 4 = 6.

two_sum([3,3], 6)
→ [0,1]

Target complexity: time O(n), space O(n)

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