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  1. #include <stdio.h>
  2.  
  3. #define M 3
  4. typedef int Marray_t[M][M];
  5.  
  6. void transpose_v1(Marray_t A) {
  7.     int i, j;
  8.     int *startAddress = &A[0][0];
  9.     for (i=0; i<M; i++) {
  10.         for (j=0; j<M; j++) {
  11.             int* y = startAddress + (i*M+j);
  12.             int* u = startAddress + (j*M+i);
  13.             int temp;
  14.             temp = *y;
  15.             *y = *u;
  16.             *u = temp;
  17.         }
  18.     }
  19. }
  20.  
  21. void transpose_v2(Marray_t A) {
  22.     int i, j;
  23.     int *startAddress = &A[0][0];
  24.     for (i=0; i<M; i++) {
  25.         for (j=0; j<i; j++) {
  26.             int* y = startAddress + (i*M+j);
  27.             int* u = startAddress + (j*M+i);
  28.             int temp;
  29.             temp = *y;
  30.             *y = *u;
  31.             *u = temp;
  32.         }
  33.     }
  34. }
  35.  
  36. void print(Marray_t A) {
  37.   int i, j;
  38.   for(i = 0; i < M; ++i) {
  39.     for(j = 0; j < M; ++j) printf("%d ", A[i][j]);
  40.     printf("\n");
  41.   }
  42. }
  43.  
  44. int main(void) {
  45. 	int arr1[M][M] = { {1, 2, 3}, {4, 5, 6}, {7, 8, 9}};
  46. 	int arr2[M][M] = { {1, 2, 3}, {4, 5, 6}, {7, 8, 9}};
  47.  
  48. 	printf("arr1:\n");
  49. 	print(arr1);
  50. 	printf("arr2:\n");
  51. 	print(arr2);
  52.  
  53. 	transpose_v1(arr1);
  54. 	transpose_v2(arr2);
  55.  
  56. 	printf("arr1:\n");
  57. 	print(arr1);
  58. 	printf("arr2:\n");
  59. 	print(arr2);
  60. 	return 0;
  61. }
  62.  
Success #stdin #stdout 0s 2292KB
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stdin
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Standard input is empty
stdout
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arr1:
1 2 3 
4 5 6 
7 8 9 
arr2:
1 2 3 
4 5 6 
7 8 9 
arr1:
1 2 3 
4 5 6 
7 8 9 
arr2:
1 4 7 
2 5 8 
3 6 9
https://ideone.com/BfiPM8
language:
C (gcc 8.3)
created:
11 years ago
visibility:
public

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