Two Sum

ref: https://leetcode.com/problems/two-sum/

const twoSum = (nums, target) => {
  const map = new Map()
  for (let i = 0; i < nums.length; i++) {
    const complement = target - nums[i]
    if (map.has(complement) && map.get(complement) !== i) {
      return [i, map.get(complement)]
    }
    map.set(nums[i], i)
  }
}

the above is the final solution as described by the author of the leetcode question.

Here are some use cases that could possibly make use of the algorithm

• organizing debit/credit card payments + refunds:
  • input your target price, and it will find the two transactions that match
• with a bit of work, it could be used to find complementary vectors in a vector embedding