第二题AC代码 nums=[[4,1],[9,3],[5,5],[2,4],[2,1]] def solution(nums): nums.sort(key=lambda x:(x[0],x[1])) res=[nums[0]] for num in nums[1:]: found=False for i in range(len(res)): if num[0]>=res[i][0] and num[1]>=res[i][1]: res[i]=num found=True break if found==False: res.append(num) return len(res) solution(nums)