def minMeetingRoom(intervals):
if intervals is None or len(intervals)==0:
return 0
tmp = []
for inter in intervals:
tmp.append((inter.start,True))
tmp.append((inter.end,False))
tmp = sorted(tmp,key=lambda v:(v[0],v[1]))
n=0
max_num=0
for arr in tmp:
if arr[1]:
n+=1
else:
n-=1
max_num = max(max_num,n)
return max_num