LC-1498 Medium LeetCode

1498. Number of Subsequences That Satisfy the Given Sum Condition

Array Two Pointers Binary Search Sorting

Read the full problem statement on LeetCode.

Difficulty: medium Acceptance: 44% Topics: Array, Two Pointers, Binary Search, Sorting

Reading material

Arrays & Hashing 12 min Two Pointers 9 min Binary Search 12 min

Reference solution (spoiler · python)

# Time:  O(nlogn)
# Space: O(n)

class Solution(object):
    def numSubseq(self, nums, target):
        """
        :type nums: List[int]
        :type target: int
        :rtype: int
        """
        MOD = 10**9 + 7
        nums.sort()
        result = 0
        left, right = 0, len(nums)-1
        while left <= right:
            if nums[left]+nums[right] > target:
                right -= 1
            else:
                result = (result+pow(2, right-left, MOD))%MOD
                left += 1
        return result

Solution from kamyu104/LeetCode-Solutions · MIT