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  1. #include <stdlib.h>
  2. #include <stdio.h>
  3. #include <string.h>
  4.  
  5. typedef int T;
  6.  
  7. T** create(int N, int M)
  8. {
  9.     T** arr = (T**)malloc(2*sizeof(int)+N*(sizeof(T*)+M*sizeof(T)));
  10.     *((int*)arr)   = N;
  11.     *((int*)arr+1) = M;
  12.     arr = (T**)((char*)arr+2*sizeof(int));
  13.  
  14.     for(int i = N, ofs = N*sizeof(T*);
  15.         i-->0; ofs += M*sizeof(T))
  16.         arr[i] = (T*)((char*)arr + ofs);
  17.  
  18.     return arr;
  19. }
  20.  
  21. void kill(T** arr)
  22. {
  23.     free((char*)arr-2*sizeof(int));
  24. }
  25.  
  26. int rows(T**arr)
  27. {
  28.     return *(int*)((char*)arr-2*sizeof(int));
  29. }
  30.  
  31. int cols(T**arr)
  32. {
  33.     return *(int*)((char*)arr-sizeof(int));
  34. }
  35.  
  36. void work(T**arr)
  37. {
  38.     for(int i = 0; i < rows(arr); ++i)
  39.         for(int j = 0; j < cols(arr); ++j)
  40.             arr[i][j] = 10*i+j;
  41.  
  42.  
  43.     for(int i = 0; i < rows(arr); ++i)
  44.     {
  45.         for(int j = 0; j < cols(arr); ++j)
  46.         {
  47.             printf("%02d  ",arr[i][j]);
  48.         }
  49.         puts("");
  50.     }
  51. }
  52.  
  53. int main(int argc, const char * argv[])
  54. {
  55.     T** arr = create(5,8);
  56.     work(arr);
  57.     kill(arr);
  58.  
  59.     puts("");
  60.  
  61.     arr = create(8,5);
  62.     work(arr);
  63.     kill(arr);
  64.  
  65. }
  66.  
Success #stdin #stdout 0s 4372KB
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https://ideone.com/ZHB1uW
language:
C (gcc 8.3)
created:
3 years ago
visibility:
public

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