Two_Sum.py

#  1. Two Sum
#  Given an array of integers nums and an integer target, return indices of the two numbers such that they add up to target.

#  You may assume that each input would have exactly one solution, and you may not use the same element twice.

#  You can return the answer in any order.
# Example 1:

# Input: nums = [2,7,11,15], target = 9
# Output: [0,1]
# Explanation: Because nums[0] + nums[1] == 9, we return [0, 1].
# Example 2:

# Input: nums = [3,2,4], target = 6
# Output: [1,2]

# solution-->

class Solution:
    def twoSum(self, nums: List[int], target: int) -> List[int]:
        result = []
    # Dictionary to store the difference and its index
        index_map = {}
    # Loop for each element
        for i, n in enumerate(nums):
        # Difference which needs to be checked
         difference = target - n
         if difference in index_map:
             result.append(i)
             result.append(index_map[difference])
             break
        else:
             index_map[n] = i
        return result