435.无重叠区间

class Solution:
 def eraseOverlapIntervals(self, intervals: List[List[int]]) - int:
 if not intervals:
 return 0
 intervals.sort(key lambda x:x[1])
 n len(intervals)
 right intervals[0][1]
 ans 1
 for i in range(1,n):
 if intervals[i][0] right:
 ans 1
 right intervals[i][1]
 return n-ans