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  1. #include <iostream>
  2. #include <vector>
  3. using namespace std;
  4.  
  5. int calculateSum(const std::vector<int> &vec)
  6. {
  7. 	int result{0};
  8. 	bool addPlus = false;
  9.  
  10. 	for (size_t i = 0; i < vec.size(); ++i) {
  11. 	    for (size_t j = i + 1; j < vec.size(); ++j) {
  12. 	    	if (addPlus) cout << "+ "; else addPlus = true;
  13. 			cout << "{" << vec[i] << " * " << vec[j] << "} ";
  14.     	    result += vec[i] * vec[j];
  15.     	}
  16. 	}
  17.  
  18. 	cout << "= " << result << endl;
  19. 	return result;
  20. }
  21.  
  22.  
  23. int main() {
  24. 	calculateSum({});
  25. 	cout << endl;
  26. 	calculateSum({1});
  27. 	cout << endl;
  28. 	calculateSum({1, 2});
  29. 	cout << endl;
  30. 	calculateSum({1, 2, 3});
  31. 	return 0;
  32. }
Success #stdin #stdout 0.01s 5568KB
comments (?)
stdin 
Standard input is empty
stdout 
= 0

= 0

{1 * 2} = 2

{1 * 2} + {1 * 3} + {2 * 3} = 11
https://ideone.com/3lKPtv
language:
C++ 4.3.2 (gcc-4.3.2)
created:
4 years ago
visibility:
public

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