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  1. #include <stdio.h>
  2.  
  3. #define BIT_IDX(X, Y)	(X + (Y << 3))
  4. #define XYBIT(X, Y)	(1ULL << BIT_IDX(X, Y))
  5. #define IF_CAN_JUMP(X, Y)	xx = x + X; yy = y + Y; if (0 <= xx && xx <= 7 && 0 <= yy && yy <= 7)
  6.  
  7. int main(void) {
  8. 	unsigned long long now;
  9. 	unsigned long long old;
  10. 	int step;
  11. 	int score[64];
  12. 	unsigned long long bit[64];
  13. 	int i;
  14. 	int x;
  15. 	int y;
  16.  
  17. 	for(i = 0; i < 64; ++i)
  18. 	{
  19. 		unsigned long long bitmap = 0;
  20. 		int x = i % 8;	int xx;
  21. 		int y = i / 8;	int yy;
  22.  
  23. 		IF_CAN_JUMP(-1, -2) bitmap |= XYBIT(xx, yy);
  24. 		IF_CAN_JUMP(-1, +2) bitmap |= XYBIT(xx, yy);
  25. 		IF_CAN_JUMP(+1, -2) bitmap |= XYBIT(xx, yy);
  26. 		IF_CAN_JUMP(+1, +2) bitmap |= XYBIT(xx, yy);
  27. 		IF_CAN_JUMP(-2, -1) bitmap |= XYBIT(xx, yy);
  28. 		IF_CAN_JUMP(-2, +1) bitmap |= XYBIT(xx, yy);
  29. 		IF_CAN_JUMP(+2, -1) bitmap |= XYBIT(xx, yy);
  30. 		IF_CAN_JUMP(+2, +1) bitmap |= XYBIT(xx, yy);
  31.  
  32. 		bit[i] = bitmap;
  33. 		score[i] = 0;
  34. 	}
  35.  
  36. 	now = XYBIT(0, 0);
  37. 	old = now;
  38. 	step = 1;
  39.  
  40. 	while (old != 0xffffffffffffffffULL)
  41. 	{
  42. 		unsigned long long to = 0;
  43.  
  44. 		while (now)
  45. 		{
  46. 			int idx = __builtin_ctzll(now);
  47. 			now &= now - 1;
  48. 			to |= bit[idx];
  49. 		}
  50.  
  51. 		now = (to & ~old);
  52. 		old |= now;
  53. 		to = now;
  54.  
  55. 		while (to)
  56. 		{
  57. 			int idx = __builtin_ctzll(to);
  58. 			to &= to - 1;
  59. 			score[idx] = step;
  60. 		}
  61. 		++step;
  62. 	}
  63.  
  64. 	printf("    1 2 3 4 5 6 7 8\n");
  65. 	printf("    ---------------\n");
  66. 	for(y = 0; y < 8; ++y)
  67. 	{
  68. 		printf("%d |", y + 1);
  69. 		for( x = 0; x < 8; ++x)
  70. 			printf(" %d", score[BIT_IDX(x, y)]);
  71. 		printf("\n");
  72. 	}
  73.  
  74. 	return 0;
  75. }
  76.  
Success #stdin #stdout 0s 2248KB
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stdin
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Standard input is empty
stdout
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    1 2 3 4 5 6 7 8
    ---------------
1 | 0 3 2 3 2 3 4 5
2 | 3 4 1 2 3 4 3 4
3 | 2 1 4 3 2 3 4 5
4 | 3 2 3 2 3 4 3 4
5 | 2 3 2 3 4 3 4 5
6 | 3 4 3 4 3 4 5 4
7 | 4 3 4 3 4 5 4 5
8 | 5 4 5 4 5 4 5 6
https://ideone.com/HDi2cj
language:
C (gcc 8.3)
created:
10 years ago
visibility:
public

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