1498. Number of Subsequences That Satisfy the Given Sum Condition

https://leetcode.com/problems/number-of-subsequences-that-satisfy-the-given-sum-condition/

Python

class Solution:
    def numSubseq(self, nums: List[int], target: int) -> int:
        nums.sort()

        l, r = 0, len(nums)-1
        counts = 0

        while l <= r:
            if nums[l] + nums[r] > target:
                r -= 1
            else:
                combs = 2 ** (r-l)
                counts += combs % (10**9 + 7)
                l += 1

        return counts % (10**9 + 7)