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  1. #include <stdio.h>
  2.  
  3. long cant=4,fila=0,colum=0,ctt=0;
  4. double a[4][5] = 
  5. {
  6. 	{1, -2, 1, 1, 2},
  7.     {3, 0, 2, -2, -8},
  8.     {0, 4, -1, -1, 1},
  9.     {5, 0, 3, -1, -3},
  10. };
  11. double res[10];
  12.  
  13. #define abs(x) ((x) > 0 ? (x) : (-x))
  14.  
  15. long jordan(){/*this do the gauss elimination for solve the equation*/
  16. 	long FilaMax=0,k=0;
  17. 	long double maxEl=0,tmp=0,fracc=0;
  18. 	for (colum=0; colum<cant-1; colum++) {
  19. 	    /* search the maximun colum*/
  20. 	    maxEl = abs(a[colum][colum]);
  21. 	    FilaMax = colum;
  22. 	    for (k=colum+1; k<cant; k++) {
  23. 	        if (abs(a[k][colum]) > maxEl) {
  24. 	            maxEl = abs(a[k][colum]);
  25. 	            FilaMax = k;
  26. 	        }
  27. 	    }
  28. 	    /* change the maximunby the actual row*/
  29. 	    for (k=colum; k<cant+1;k++) {
  30. 	        tmp = a[FilaMax][k];
  31. 	        a[FilaMax][k] = a[colum][k];
  32. 	        a[colum][k] = tmp;
  33. 	    }
  34. 	    /*lower cero's triangular matrix it's done here*/
  35. 	    for (k=colum+1;k<cant; k++) {
  36. 	        fracc = -a[k][colum]/a[colum][colum];
  37. 	        for (fila=colum; fila<cant+1; fila++) {
  38. 	            if (colum==fila) {
  39. 	                a[k][fila] = 0;
  40. 	            }else{
  41. 	                a[k][fila] += fracc * a[colum][fila];
  42. 	            }
  43. 	        }
  44. 	     } 
  45. 	}
  46.  
  47. 	printf("%f\n", (float)a[cant-1][cant-1]);
  48.     if(abs(a[cant-1][cant-1])<0.000001)
  49. 		printf("no solution found\n");
  50. 		else
  51. 		printf("solution found\n");
  52.  
  53. }
  54.  
  55. int main(void) {
  56. 	// your code goes here
  57. 	jordan();
  58. 	return 0;
  59. }
  60.  
Success #stdin #stdout 0s 2008KB
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Standard input is empty
stdout
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0.000000
no solution found
https://ideone.com/lWRRaU
language:
C (gcc 8.3)
created:
9 years ago
visibility:
secret

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