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  1. #include <stdlib.h>
  2. #include <stdio.h>
  3. #include <inttypes.h>
  4.  
  5. int main()
  6. {
  7. 	int n = 2;
  8. 	int m = 3;
  9. //	int i[2][3] = { {1, 2, 3}, {4, 5, 6} };
  10. 	int * i = (int*)malloc(sizeof(int) * n * m);	// i[n][m]
  11. 	for(int j = 0; j < n * m; ++j) i[j] = j + 1;
  12. 	for(int j = 0; j < n; ++j)
  13. 	{
  14. 		for(int k = 0; k < m; ++k)
  15. 			printf("%d ", *(i + j * m + k));
  16. 		printf("\n");
  17. 	}
  18.  
  19. 	int (*ii)[m] = (int(*)[m]) i;
  20. 	for(int j = 0; j < n; ++j)
  21. 	{
  22. 		for(int k = 0; k < m; ++k)
  23. 			printf("%d ", ii[j][k]); 
  24. 		printf("\n");
  25. 	}
  26. 	ii = (int(*)[m]) i;
  27. 	printf("i: 0x%p\n", i);
  28. 	printf("ii: 0x%p\n", ii);
  29. 	printf("sizeof(i): %" PRIuPTR "\n", sizeof(i));
  30. 	printf("sizeof(*i): %" PRIuPTR "\n", sizeof(*i));
  31. 	printf("sizeof(ii): %" PRIuPTR "\n", sizeof(ii));
  32. 	printf("sizeof(*ii): %" PRIuPTR "\n", sizeof(*ii));
  33. 	free(i);
  34. }
Success #stdin #stdout 0s 5400KB
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stdin
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Standard input is empty
stdout
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1 2 3 
4 5 6 
1 2 3 
4 5 6 
i: 0x0x559f9da69260
ii: 0x0x559f9da69260
sizeof(i): 8
sizeof(*i): 4
sizeof(ii): 8
sizeof(*ii): 12
https://ideone.com/tYeGHY
Testing the pointer to an array.
language:
C++14 (gcc 8.3)
created:
3 years ago
visibility:
public

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