There is a bug in leetcode test cases: Input:	2,[set(2,1),set(2,2),get(2),set(1,1),set(4,1),get(2)] Output:	[2,2] Expected:	[2,-1]
There is a bug in leetcode test cases:
Input:	2,[set(2,1),set(2,2),get(2),set(1,1),set(4,1),get(2)]
Output:	[2,2]
Expected:	[2,-1]

jialing3/corner_cases,jialing3/corner_cases