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  1. #include <stdio.h>
  2.  
  3. #define VALID(x) ((x) >= 0 && (x) < 3)
  4.  
  5. int arr[3][3] = { {1,2,3}, {4,5,6}, {7,8,9} };
  6.  
  7. // to detect previous visited cells and eliminate infinite recursion
  8. short vis[3][3] = { 0 }; 
  9.  
  10. int xtar, ytar; // destination cell
  11. int xsrc, ysrc; // source cell
  12.  
  13. // to move in directions: down, up, right, and left, respectively
  14. const int dirx[] = { 0, 0, 1, -1 };
  15. const int diry[] = { 1, -1, 0, 0 };
  16.  
  17. // temp buffer to print paths
  18. // max size = size of arr + zero termination char
  19. char tmp_path[3 * 3 + 1];
  20.  
  21. void rec(int x, int y, int idx) // idx is used to fill tmp_path
  22. {
  23.    int i;
  24.    if (vis[y][x]) return; // already visited
  25.    tmp_path[idx] = arr[y][x] + '0';
  26.    if (x == xtar && y == ytar) // basic case
  27.    {
  28.       tmp_path[idx + 1] = 0; // put zero char
  29.       printf("%s\n", tmp_path); // print path
  30.       return;
  31.    }
  32.    vis[y][x] = 1; // otherwise, mark as visited
  33.    for (i = 0; i < 4; ++i) // for each of the 4 directions
  34.       if (VALID(y + diry[i]) && VALID(x + dirx[i]))
  35.          rec(x + dirx[i], y + diry[i], idx + 1);
  36.    vis[y][x] = 0; // reset visited so that can be visited again
  37. }
  38.  
  39. main()
  40. {
  41.    // input xtar, ytar, xsrc, ysrc, arr
  42.    xtar = 1;
  43.    ytar = 2;
  44.    xsrc = 0;
  45.    ysrc = 0;
  46.    rec(xsrc, ysrc, 0);
  47. }
Success #stdin #stdout 0s 2248KB
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stdin
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Standard input is empty
stdout
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1478
1458
14523698
145698
1258
125698
125478
123698
123658
12365478
https://ideone.com/GqWLa5
language:
C (gcc 8.3)
created:
10 years ago
visibility:
public

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