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  1.  
  2.  
  3. #include <bits/stdc++.h>
  4. using namespace std;
  5.  
  6. int countKdivPairs(int A[], int n, int K)
  7. {
  8.     map<int,int> freq;
  9.     set<int> s;
  10.     int ans = 0;
  11.     for (int i = 0; i < n; i++) {
  12.     	if(s.find(A[i])==s.end())
  13.     	{
  14.         	int rem = A[i] % K;
  15.         	ans += 2*freq[(K - rem) % K];
  16.         	freq[rem]++;
  17.         	if((A[i]+A[i])%K==0)
  18.         		ans++;
  19.         	cout<<A[i]<<" "<<ans<<"\n";
  20.     	}
  21.     	s.insert(A[i]);
  22.     }
  23.     return ans;
  24. }
  25.  
  26. int main()
  27. {
  28.  
  29.     int A[] = {0,1,2,3};
  30.     int n = sizeof(A) / sizeof(A[0]);
  31.     int K = 2;
  32.     cout << countKdivPairs(A, n, K);
  33.  
  34.     return 0;
  35. }
Success #stdin #stdout 0s 4896KB
comments (?)
stdin
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Standard input is empty
stdout
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0 1
1 2
2 5
3 8
8
https://ideone.com/OjcW6W
language:
C++14 (gcc 8.3)
created:
3 years ago
visibility:
public

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