Minimum Absolute Difference

Problem Statement - link #

Given an array of distinct integers arr, find all pairs of elements with the minimum absolute difference of any two elements.

Return a list of pairs in ascending order(with respect to pairs), each pair [a, b] follows

• a, b are from arr
• a < b
• b - a equals to the minimum absolute difference of any two elements in arr

Examples #

Example 1:

Input: arr = [4,2,1,3]
Output: [[1,2],[2,3],[3,4]]
Explanation: The minimum absolute difference is 1. List all pairs with difference equal to 1 in ascending order.

Example 2:

Input: arr = [1,3,6,10,15]
Output: [[1,3]]

Example 3:

Input: arr = [3,8,-10,23,19,-4,-14,27]
Output: [[-14,-10],[19,23],[23,27]]

Constraints #

• 2 <= arr.length <= 10^5
• -10^6 <= arr[i] <= 10^6

Solutions #

class Solution {
public:
    vector<vector<int>> minimumAbsDifference(vector<int>& arr) {
      vector<vector<int>> res;
      int md = INT_MAX;
      sort(arr.begin(),arr.end());
      for(int i=1; i<arr.size(); i++){
        int m = arr[i]-arr[i-1];
        if(m==md){ res.push_back({arr[i-1],arr[i]}); }
        if(m < md){
          res = {};
          res.push_back({arr[i-1],arr[i]});
          md = m;
        }
      }
      return res;
    }
};