ToDo

Date	Type	Note
7/24	#724, #01, #747	找出 array 裡最大 val 之應用題只要找出第二大就行
7/25	#66 , #14, #344, #561, #167, #27	Two pointer, [ arr[0], arr[1] ] = [ [arr[1], arr[0] ]
7/26	#485	Math.max()