def test1(nums, target): nums.sort() #先排序 left,right = 0,len(nums)-1 n = 0 while(left < right): if(nums[left] + nums[right] > target): right -= 1 else: n += (right - left) left += 1 return n%(10**9+7) nums = [2,2,1,9] target = 10 print(test1(nums,target))