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  1. #include <iostream>
  2. #include <cstdlib>
  3. int** matrix_create(int N, int M);
  4. void  matrix_free(int** mat, int N);
  5. int** matrix_miltiply(int& N, int& M, int** m1, int N1, int M1, int** m2, int N2, int M2);
  6. void  matrix_rand(int** m, int N, int M, int num);
  7. void  matrix_print(std::ostream& _out, int** m, int N, int M);
  8.  
  9.  
  10. int main(void){
  11. 	int   N1 = 5, M1 = 3;
  12. 	int** m1 = matrix_create(N1, M1);
  13. 	if(m1 == NULL)
  14. 		return 1;
  15.  
  16. 	int   N2 = M1, M2 = 8;
  17. 	int** m2 = matrix_create(N2, M2);
  18. 	if(m2 == NULL)
  19. 		return 1;
  20.  
  21. 	matrix_rand(m1, N1, M1, 5);
  22. 	matrix_rand(m2, N2, M2, 7);
  23.  
  24. 	int N3, M3;
  25. 	int** m3 = matrix_miltiply(N3, M3, m1, N1, M1, m2, N2, M2);
  26. 	if(m3 == NULL)
  27. 		return 1;
  28.  
  29. 	matrix_print(std::cout, m1, N1, M1);
  30. 	matrix_print(std::cout, m2, N2, M2);
  31. 	matrix_print(std::cout, m3, N3, M3);
  32.  
  33. 	matrix_free(m1, N1);
  34. 	matrix_free(m2, N2);
  35. 	matrix_free(m3, N3);
  36. 	return 0;
  37. }
  38.  
  39. //перемножение матриц
  40. int** matrix_miltiply(int& N, int& M, int** m1, int N1, int M1, int** m2, int N2, int M2){
  41. 	if(M1 != N2)
  42. 		return NULL;
  43.  
  44. 	int** m3 = matrix_create(N1, M2);
  45. 	if(m3 == NULL)
  46. 		return NULL;
  47.  
  48. 	for(int i = 0; i < N1; ++i){
  49. 		for(int j = 0; j < M2; ++j){
  50. 			m3[i][j] = 0;
  51. 			for(int k = 0; k < N2; ++k)
  52. 				m3[i][j] += m1[i][k] * m2[k][j];
  53. 		}
  54. 	}
  55. 	N = N1, M = M2;
  56. 	return m3;
  57. }
  58.  
  59. //выделение памяти для матрицы
  60. int** matrix_create(int N, int M){
  61. 	int** mat = new (std::nothrow) int*[N];
  62. 	if(mat == NULL)
  63. 		return NULL;
  64.  
  65. 	for(int i = 0; i < N; ++i){
  66. 		mat[i] = new (std::nothrow) int[M];
  67. 		if(mat[i] == NULL){
  68. 			matrix_free(mat, i);
  69. 			mat = NULL;
  70. 			break;
  71. 		}
  72. 	}
  73. 	return mat;
  74. }
  75.  
  76. //удаление памяти
  77. void matrix_free(int** mat, int N){
  78. 	if(mat != NULL){
  79. 		for(int i = 0; i < N; ++i)
  80. 			delete[] mat[i];
  81. 		delete[] mat;
  82. 	}
  83. }
  84.  
  85. //заполнение
  86. void matrix_rand(int** m, int N, int M, int num){
  87. 	for(int i= 0 ; i < N; ++i){
  88. 		for(int j = 0; j < M; ++j)
  89. 			m[i][j] = rand() % num;
  90. 	}
  91. }
  92.  
  93. //печать
  94. void matrix_print(std::ostream& _out, int** m, int N, int M){
  95. 	for(int i= 0 ; i < N; ++i){
  96. 		for(int j = 0; j < M; ++j)
  97. 			_out << m[i][j] << ' ';
  98. 		_out << std::endl;
  99. 	}
  100. 	_out << std::endl;	
  101. }
Success #stdin #stdout 0s 3464KB
comments (?)
stdin
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Standard input is empty
stdout
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3 1 2 
0 3 0 
1 2 4 
1 2 2 
0 4 3 

0 3 1 2 2 3 0 5 
2 2 5 5 6 1 5 5 
0 3 5 3 2 1 0 2 

2 17 18 17 16 12 5 24 
6 6 15 15 18 3 15 15 
4 19 31 24 22 9 10 23 
4 13 21 18 18 7 10 19 
8 17 35 29 30 7 20 26
https://ideone.com/NYSiLd
language:
C++ (gcc 8.3)
created:
7 years ago
visibility:
public

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