leetcode2-LeetCode.swift:菜鸟的解题之路

leetcode 2 LeetCode.swift愚者千焦，必有得。作为算法的白痴，我大胆解决.上的问题，尤其是.大多数算法不是我自己想出来的。let :smiling_face_with_sunglasses: = " Easy " , :neutral_face: = " Medium " , :fearful_face: = " Hard " , :Japanese_secret_button: = " require premium membership " 1 :smiling_face_with_sunglasses: 2 :neutral_face: 3 :neutral_face: 4 :fearful_face: 5 :neutral_face: 6 :neutral_face: 7 :smiling_face_with_sunglasses: 8 :neutral_face: 9 :smiling_face_with_sunglasses: 10 :fearful_face: 11 :neutral_face: 12 :neutral_face: 13 :smiling_face_with_sunglasses: 14 :smiling_face_with_sunglasses: 15 :neutral_face: 16 :neutral_face: 17 :neutral_face: 18 :neutral_face: 19 :neutral_face: 20 :smiling_face_with_sunglasses: 21 :smiling_face_with_sunglasses: 22 :neutral_face: 23 :fearful_face: 24 :neutral_face: 25 :fearful_face: 26 :smiling_face_with_sunglasses: 27 :smiling_face_with_sunglasses: 28 :smiling_face_with_sunglasses: 29 :neutral_face: 30 :fearful_face: 31 :neutral_face: 32 :fearful_fa