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  1. import java.util.*;
  2.  
  3. public class Main {
  4.     private static int digitSum(int n) {
  5.         int sum = 0;
  6.         while (n > 0) {
  7.             sum += n % 10;
  8.             n /= 10;
  9.         }
  10.         return sum;
  11.     }
  12.  
  13.     public static void main(String[] args) {
  14.         int[] nums = {51, 71, 17, 42};
  15.  
  16.         Map<Integer, PriorityQueue<Integer>> map = new HashMap<>();
  17.  
  18.         // Step 1: Group by digit sum
  19.         for (int num : nums) {
  20.             int sum = digitSum(num);
  21.             map.putIfAbsent(sum, new PriorityQueue<>(Collections.reverseOrder()));
  22.             map.get(sum).add(num);
  23.         }
  24.  
  25.         int maxSum = -1;
  26.         List<int[]> maxPairs = new ArrayList<>();
  27.  
  28.         // Step 2: For each group, check top 2 numbers
  29.         for (PriorityQueue<Integer> pq : map.values()) {
  30.             if (pq.size() >= 2) {
  31.                 int first = pq.poll();
  32.                 int second = pq.poll();
  33.                 int sum = first + second;
  34.  
  35.                 if (sum > maxSum) {
  36.                     maxSum = sum;
  37.                     maxPairs.clear();
  38.                     maxPairs.add(new int[]{first, second});
  39.                 } else if (sum == maxSum) {
  40.                     maxPairs.add(new int[]{first, second});
  41.                 }
  42.             }
  43.         }
  44.  
  45.         // Output result
  46.         System.out.println("Maximum Sum: " + maxSum);
  47.         System.out.println("Pairs:");
  48.         for (int[] pair : maxPairs) {
  49.             System.out.println(pair[0] + " " + pair[1]);
  50.         }
  51.     }
  52. }
  53.  
Success #stdin #stdout 0.19s 57636KB
comments (?)
stdin 
6 
12 33 6 85 51 42
stdout 
Maximum Sum: 93
Pairs:
51 42
https://ideone.com/3Icq6l
language:
Java (HotSpot 12)
created:
22 days ago
visibility:
public

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