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  1. #include <bits/stdc++.h>
  2. using namespace std;
  3. int n;
  4. vector<vector<double>> A;
  5.  
  6. void ge() {
  7. 	// Forward Elimination
  8. 	for (int k = 0; k < n; k++) {
  9. 		for (int i = k + 1; i < n; i++) {
  10. 			double r = A[i][k] / A[k][k];
  11. 			for (int j = k; j <= n; j++) {
  12. 				A[i][j] -= r * A[k][j];
  13. 			}
  14. 		}
  15. 	}
  16.  
  17. 	// Back Substitution
  18. 	vector<double> ans(n);
  19. 	for (int i = n - 1; i >= 0; i--) {
  20. 		ans[i] = A[i][n];
  21. 		for (int j = i + 1; j < n; j++) {
  22. 			ans[i] -= A[i][j] * ans[j];
  23. 		}
  24. 		ans[i] /= A[i][i];
  25. 	}
  26.  
  27. 	// Printing Result
  28. 	cout << "\nSolutions:\n";
  29. 	for (int i = 0; i < n; i++) {
  30. 		cout << "x" << i + 1 << " : " << ans[i] << endl;
  31. 	}
  32. }
  33.  
  34. int main() {
  35. 	cout << "Enter vars: \n";
  36. 	cin >> n;
  37. 	A = vector<vector<double>>(n, vector<double>(n + 1, 0));
  38.  
  39. 	cout << "Enter the augmented matrix (row-wise):\n";
  40. 	for (int i = 0; i < n; i++) {
  41. 		for (int j = 0; j <= n; j++) {
  42. 			cin >> A[i][j];
  43. 		}
  44. 	}
  45.  
  46. 	ge();
  47. 	return 0;
  48. }
Success #stdin #stdout 0.01s 5288KB
comments (?)
stdin
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3
5 10 1 28
1 1 1 6
4 8 3 29
stdout
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Enter vars: 
Enter the augmented matrix (row-wise):

Solutions:
x1 : 1
x2 : 2
x3 : 3
https://ideone.com/uMMa3Y
Gauss Elimination
language:
C++14 (gcc 8.3)
created:
8 days ago
visibility:
public

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