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  1. #include <bits/stdc++.h>
  2. using namespace std;
  3.  
  4. int main() {
  5. 	// your code goes here
  6. 	int n;
  7. 	cin>>n;
  8. 	vector<int>arr(n);
  9. 	for(int i=0;i<n;i++){
  10. 		cin>>arr[i];
  11. 	}
  12. 	sort(arr.begin(),arr.end());
  13. 	int k;
  14. 	cin>>k;
  15. 	int count=0;
  16. 	for(int i=0,j=n-1;i<n;i++){
  17. 		int sum=arr[i]+arr[j];
  18. 		while(sum>k && i!=j){
  19. 			j--;
  20. 			sum=arr[i]+arr[j];
  21. 		}
  22. 		if(i==j){
  23. 			break;
  24. 		}
  25. 		count=count+(j-i);
  26. 	}
  27.  
  28. 	cout<<count;
  29. 	return 0;
  30. }
Success #stdin #stdout 0s 5268KB
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stdin
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6
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stdout
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4
https://ideone.com/aJLKNR
language:
C++ (gcc 8.3)
created:
4 days ago
visibility:
public

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