Minimum Absolute Difference

Zhuoqun Li bio photo By Zhuoqun Li

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

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

Solution:

Easy.

class Solution {
public:
    vector<vector<int>> minimumAbsDifference(vector<int>& arr) {
        sort(arr.begin(),arr.end());
        int mina = INT_MAX;
        for(int i =0 ;i <arr.size()-1;i++){
            if(arr[i+1]-arr[i] < mina) mina = arr[i+1]-arr[i];
        }
        vector<vector<int>> ans;
        for(int i =0 ;i <arr.size()-1;i++){
            if(arr[i+1]-arr[i] == mina) ans.push_back(vector<int>{arr[i],arr[i+1]});
        }
        return ans;
    }
};