Given nums = [2, 7, 11, 15], target = 9, Because nums[0] + nums[1] = 2 + 7 = 9, return [0, 1].
def twoSum(nums,target): res = [] i = 0 while i <len(nums): if target-nums[i] in set(nums[i:]): res.append(i) break i += 1 while nums[i]!=target-nums[res[0]]: i+=1 res.append(i) return res nums = [2,7,11,15] target = 9 print(twoSum(nums,target))