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  1. #include <type_traits>
  2. #include <vector>
  3. #include <iostream>
  4.  
  5. namespace
  6. {
  7.     template <typename Container>
  8.     struct value_type_i
  9.     {
  10.         typedef typename std::decay<
  11.             decltype(*std::begin(std::declval<
  12.                 Container const &
  13.             >()))
  14.         >::type type;
  15.     };
  16.  
  17.     template <typename Container>
  18.     using value_type = typename value_type_i<Container>::type;
  19. }
  20.  
  21. template <typename MatrixType>
  22. MatrixType transpose(MatrixType const & matrix)
  23. {
  24.     auto const nrows = matrix.size();
  25.     auto const ncols = nrows > 0 ? matrix[0].size() : 0;
  26.  
  27.     MatrixType transposed(ncols, value_type<MatrixType>(nrows));
  28.     for(auto k = 0; k < nrows; ++k)
  29.         for(auto j = 0; j < ncols; ++j)
  30.             transposed[j][k] = matrix[k][j];
  31.  
  32.     return transposed;
  33. }
  34.  
  35. template <typename T>
  36. void print(T const & t)
  37. {
  38. 	for(auto const & row : t)
  39. 	{
  40. 		for(auto const & col : row)
  41. 			std::cout << col << ' ';
  42. 		std::cout << '\n';
  43. 	}
  44. 	std::cout << '\n';
  45. }
  46.  
  47. int main()
  48. {
  49. 	std::vector<std::vector<int>> A(7, std::vector<int>(9));
  50. 	int val = 11;
  51. 	for(auto & row : A)
  52. 		for(auto & col : row)
  53. 			col = val++;
  54. 	print(A);
  55. 	print(transpose(A));
  56.  
  57. 	return 0;
  58. }
Success #stdin #stdout 0s 3432KB
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stdin
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Standard input is empty
stdout
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11 12 13 14 15 16 17 18 19 
20 21 22 23 24 25 26 27 28 
29 30 31 32 33 34 35 36 37 
38 39 40 41 42 43 44 45 46 
47 48 49 50 51 52 53 54 55 
56 57 58 59 60 61 62 63 64 
65 66 67 68 69 70 71 72 73 

11 20 29 38 47 56 65 
12 21 30 39 48 57 66 
13 22 31 40 49 58 67 
14 23 32 41 50 59 68 
15 24 33 42 51 60 69 
16 25 34 43 52 61 70 
17 26 35 44 53 62 71 
18 27 36 45 54 63 72 
19 28 37 46 55 64 73
https://ideone.com/cCAyFD
language:
C++14 (gcc 8.3)
created:
12 years ago
visibility:
public

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