Given an array of integers, return indices of the two numbers such that they add up to a specific target.
You may assume that each input would have exactly one solution, and you may not use the same element twice.
Given nums = [2, 7, 11, 15], target = 9, Because nums + nums = 2 + 7 = 9, return [0, 1].
- loop through the array
- store each number’s complement number
target - nums[i]in a new array
- check the complement array to see if the current number exist