1200. Minimum Absolute Difference

Minimum Absolute Difference - LeetCode 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

  • code
class Solution:
    def minimumAbsDifference(self, arr: List[int]) -> List[List[int]]:
        arr.sort()
        min_d = inf
        res = []
        for i in range(1, len(arr)):
            cur_d = arr[i] - arr[i-1]
            if cur_d < min_d:
                res = [[arr[i-1], arr[i]]]
                min_d = cur_d
            elif cur_d == min_d:
                res.append([arr[i-1], arr[i]])
        return res
class Solution {
    public List<List<Integer>> minimumAbsDifference(int[] arr) {
        int min = arr[0], max = arr[0], shift;
        for (int num: arr){
            min = Math.min(min, num);
            max = Math.max(max, num);
        }
        shift = -min;
        
        int[] line = new int[max - min + 1];
        for (int num: arr){
            line[num + shift] = 1;
        }
        
        List<List<Integer>> res = new ArrayList();
        int last_i = 0;
        int min_diff = max - min;
        for (int i = 1; i < line.length; ++i){
            if (line[i] == 1){
                if (i - last_i < min_diff){
                    res = new ArrayList();
                    res.add(Arrays.asList(last_i - shift, i - shift));
                    min_diff = i - last_i;
                }
                else if (i - last_i == min_diff){
                    res.add(Arrays.asList(last_i - shift, i - shift));
                }
                last_i = i;
            }
        }
        return res;
    }
}