2563

Author: ramtanniru

Nov-13-24.py

@@ -0,0 +1,14 @@
+class Solution:
+ def countFairPairs(self, nums: List[int], lower: int, upper: int) -> int:
+ def countPairsSum(val):
+ l,r = 0,len(nums)-1
+ res = 0
+ while l<r:
+ while l<r and nums[l]+nums[r]>val:
+ r -= 1
+ res += r-l
+ l += 1
+ return res
+ ans = 0
+ nums.sort()
+ return countPairsSum(upper) - countPairsSum(lower-1)