Suppose we have an array nums and that is sorted in non-decreasing order. We have to make an array called result with the same length as nums such that result[i] is the summation of absolute differences between nums[i] and all the other elements in the array.
So, if the input is like nums = [5,7,12], then the output will be [9, 7, 12] because
- |5-5| + |5-7| + |5-12| = 0+2+7 = 9
- |7-5| + |7-7| + |7-12| = 2+0+5 = 7
- |5-12| + |7-12| + |12-12| = 7+5+0 = 12
To solve this, we will follow these steps −
- res := a new list
- s:= 0
- n := size of nums
- for i in range 1 to n - 1, do
- s := s + nums[i] - nums[0]
- insert s at the end of res
- for i in range 1 to n - 1, do
- diff := nums[i] - nums[i-1]
- s := s + diff*i
- s := s - diff *(n-i)
- insert s at the end of res
- return res
Example
Let us see the following implementation to get better understanding −
def solve(nums): res = [] s=0 n = len(nums) for i in range(1,n): s+=nums[i]-nums[0] res.append(s) for i in range(1,n): diff = nums[i]-nums[i-1] s += diff*i s -= diff *(n-i) res.append(s) return res nums = [5,7,12] print(solve(nums))
Input
[5,7,12]
Output
[9, 7, 12]