Problem 3: Left and Right Sum Differences (easy)

Problem Statement

Given an input array of integers nums, find an integer array, let's call it differenceArray, of the same length as an input integer array.

Each element of differenceArray, i.e., differenceArray[i], should be calculated as follows: take the sum of all elements to the left of index i in array nums (let's call it leftSumⁱ), and subtract it from the sum of all elements to the right of index i in array nums (let's call it rightSumⁱ), taking the absolute value of the result:

differenceArray[i] = | leftSumⁱ - rightSumⁱ |

If there are no elements to the left or right of i, the corresponding sum should be taken as 0.

Examples

Example 1:

• Input: nums = [2, 5, 1, 6, 1]
• Expected Output: [13, 6, 0, 7, 14]
• Explanation:
  • For i=0: |(0) - (5+1+6+1)| = |0 - 13| = 13
  • For i=1: |(2) - (1+6+1)| = |2 - 8| = 6
  • For i=2: |(2+5) - (6+1)| = |7 - 7| = 0
  • For i=3: |(2+5+1) - (1)| = |8 - 1| = 7
  • For i=4: |(2+5+1+6) - (0)| = |14 - 0| = 14

Example 2:

• Input: nums = [3, 3, 3]
• Expected Output: [6, 0, 6]
• Explanation:
  • For i=0: |(0) - (3+3)| = 6
  • For i=1: |(3) - (3)| = 0
  • For i=2: |(3+3) - (0)| = 6

Example 3:

• Input: nums = [1, 2, 3, 4, 5]
• Expected Output: [14, 11, 6, 1, 10]
• Explanation:
  • Calculations for each index i will follow the above-mentioned logic.

Constraints:

• 1 <= nums.length <= 1000
• 1 <= nums[i] <= 10⁵

Try it yourself