fork download 
  1. import java.util.*;
  2.  
  3. class Ideone {
  4.     public static void main(String[] args) {
  5.         Scanner sc = new Scanner(System.in);
  6.  
  7.         int sum = sc.nextInt();   
  8.         int n = sc.nextInt();
  9.         int arr[] = new int[n];
  10.  
  11.         for (int i = 0; i < n; i++) {
  12.             arr[i] = sc.nextInt();
  13.         }
  14.  
  15.         HashMap<Integer, Integer> hm = new HashMap<>();
  16.         int count = 0;
  17.  
  18.         for (int i = 0; i < n; i++) {
  19.             int a = arr[i];
  20.  
  21.  
  22.             int targetValue = a + sum;
  23.             if (hm.containsKey(targetValue)) {
  24.                 count += hm.get(targetValue);
  25.             }
  26.  
  27.  
  28.             int targetValue2 = a - sum;
  29.             if (hm.containsKey(targetValue2)) {
  30.                 count += hm.get(targetValue2);
  31.             }
  32.  
  33.             hm.put(a, hm.getOrDefault(a, 0) + 1);
  34.         }
  35.  
  36.         System.out.println(count);
  37.     }
  38. }
Success #stdin #stdout 0.18s 56648KB
comments (?)
stdin 
4
2
2
2
stdout 
0
https://ideone.com/peBml7
language:
Java (HotSpot 12)
created:
1 day ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!