- Difficulty: Hard
- Tags: LeetCode, Hard, Array, Math, Binary Search, Prefix Sum, leetcode-1862, O(nlogn), O(n)
Problem
Given an integer array nums
, return the sum of floor(nums[i] / nums[j])
for all pairs of indices 0 <= i, j < nums.length
in the array. Since the answer may be too large, return it modulo 109 + 7
.
The floor()
function returns the integer part of the division.
Example 1:
Input: nums = [2,5,9] Output: 10 Explanation: floor(2 / 5) = floor(2 / 9) = floor(5 / 9) = 0 floor(2 / 2) = floor(5 / 5) = floor(9 / 9) = 1 floor(5 / 2) = 2 floor(9 / 2) = 4 floor(9 / 5) = 1 We calculate the floor of the division for every pair of indices in the array then sum them up.
Example 2:
Input: nums = [7,7,7,7,7,7,7] Output: 49
Constraints:
1 <= nums.length <= 105
1 <= nums[i] <= 105