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  1. #include <stdio.h>
  2. #include <conio.h>
  3.  
  4.  
  5. float subMatrix(float *mat, int nSize);
  6. void copySubMatrix(float *oMat, float *iMat, int nSize, int posM, int posN);
  7. float result[16];
  8.  
  9. #define N_SIZE 4
  10.  
  11. int main(void)
  12. {
  13. 	float mat[N_SIZE][N_SIZE]={
  14. 				1,2,3,4,
  15. 				3,6,7,8,
  16. 				1,3,3,5,
  17. 				5,6,9,8
  18. 				};
  19.  
  20. 	float *MatIn = &mat[0][0];
  21. 	float result[N_SIZE][N_SIZE];
  22.  
  23. 	float det = 0;	
  24.  
  25. 	int i, j, nSize = N_SIZE;
  26.  
  27. 	for(i=0; i<nSize; ++i)
  28. 	{
  29. 		for(j=0; j<nSize; ++j)
  30. 		{
  31. 			float *p_Copy = new float[(nSize-1)*(nSize-1)];
  32. 			copySubMatrix(p_Copy, MatIn, nSize, i, j);
  33. 			if((i+j)%2)	result[i][j] = 0 - subMatrix(p_Copy, nSize-1);
  34. 			else		result[i][j] = subMatrix(p_Copy, nSize-1);
  35. 			delete [] p_Copy;
  36. 		}
  37. 	}
  38.  
  39. 	for(i=0; i<nSize; ++i)
  40. 	{
  41. 		det +=result[0][i] *  mat[0][i];
  42. 		printf("det = %f\n", det);
  43. 	}
  44. 	if(det)
  45. 	{
  46. 		for(i=0; i<nSize; ++i)
  47. 		{
  48. 			for(j=0; j<nSize; ++j)
  49. 			{
  50. 				printf("%.2f\t", result[j][i]/det);
  51. 			}
  52. 			printf("\n");
  53. 		}
  54. 	}
  55.  
  56.  
  57.  
  58.  
  59.  
  60. 	getch();
  61. 	return 0;
  62. }
  63.  
  64. //get det(mat)
  65. float subMatrix(float *mat, int nSize)
  66. {
  67. 	int i,j;
  68. 	float det = 0;
  69. 	if(nSize==2)
  70. 	{
  71. 		printf("%.1f * %.1f - %.1f * %.1f =%.1f \n",mat[0] , mat[3], mat[1], mat[2] ,mat[0] * mat[3] - mat[1] * mat[2]);
  72. 		return mat[0] * mat[3] - mat[1] * mat[2];
  73. 	}
  74.  
  75. 	//else case
  76. 	for(i=0; i<nSize; ++i)
  77. 	{
  78. 		for(j=0; j<nSize; ++j)
  79. 		{
  80. 			float *p_Copy = new float[(nSize-1)*(nSize-1)];
  81. 			copySubMatrix(p_Copy, mat, nSize, i, j);
  82. 			if((i+j)%2)	det -= mat[(i*nSize+j)]* subMatrix(p_Copy, nSize-1);
  83. 			else		det += mat[(i*nSize+j)]* subMatrix(p_Copy, nSize-1);
  84. 			delete [] p_Copy;
  85.  
  86. 		}
  87. 	}
  88. 	return det;
  89.  
  90. }
  91.  
  92. void copySubMatrix(float *oMat, float *iMat, int nSize, int posM, int posN)
  93. {
  94. 	int i,j,oIndex = 0, iIndex;
  95.  
  96. 	for(i=0; i<nSize-1; ++i)
  97. 	{
  98. 		for(j=0; j<nSize-1; ++j)
  99. 		{
  100. 			iIndex = (i<posM)? i*nSize : (i+1)*nSize;
  101. 			iIndex += (j<posN)? j: (j+1);
  102. 			oMat[oIndex] = iMat[iIndex];
  103.  
  104. 			printf("%.1f\t", oMat[oIndex]);
  105. 			oIndex++;
  106. 		}
  107. 		printf("\n");
  108. 	}
  109. 	printf("\n");
  110. //	getch();
  111. }
  112.  
  113.  
  114.  
Compilation error #stdin compilation error #stdout 0s 0KB
comments (?)
stdin
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Standard input is empty
compilation info 
prog.cpp:2:19: fatal error: conio.h: No such file or directory
 #include <conio.h>
                   ^
compilation terminated.
stdout
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Standard output is empty
https://ideone.com/BBkcqo
language:
C++ (gcc 8.3)
created:
10 years ago
visibility:
public

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