Source code for submission s1224

Go to diff to previous submission

ants.c

  1. #include <stdio.h>
  2.  
  3. #define LEFT 'L'
  4. #define RIGHT 'R'
  5. #define NONE '\0'
  6.  
  7. int falltime(int position, char direction, int length) {
  8. 	if (direction == 'R') {
  9. 		return length - position;
  10. 	}
  11.  
  12. 	return position;
  13. }
  14.  
  15. char directions[100000];
  16.  
  17. int main(void) {
  18. 	int length, count, position, time, max_time, i, l, r, last_left_going_left, last_left_going_right, last_right_going_left, last_right_going_right, max, max2, pos, pos2;
  19. 	int posibilities[4], posibilities_directions[4];
  20. 	char direction;
  21.  
  22. 	while (scanf("%d %d", &length, &count) == 2) {
  23. 		for (i = 0; i <= length; ++i) {
  24. 			directions[i] = NONE;
  25. 		}
  26.  
  27. 		max_time = -1;
  28.  
  29. 		i = count;
  30.  
  31. 		while (i--) {
  32. 			scanf("%d %c", &position, &direction);
  33.  
  34. 			time = falltime(position, direction, length);
  35.  
  36. 			if (time > max_time) {
  37. 				max_time = time;
  38. 			}
  39.  
  40. 			directions[position] = direction;
  41. 		}
  42.  
  43. 		last_left_going_right = length + 1;
  44. 		last_right_going_left = -1;
  45. 		last_left_going_left = -1;
  46. 		last_right_going_right = -1;
  47.  
  48. 		for (i = count, l = 0, r = length; l <= length && r >= 0; ++l, --r) {
  49. 			if (directions[l] == RIGHT) {
  50. 				last_left_going_right = l;
  51.  
  52. 			} else if (directions[l] == LEFT) {
  53. 				if (last_left_going_right < l) {
  54. 					directions[last_left_going_right] = NONE;
  55. 					--i;
  56. 					last_left_going_left = last_left_going_right;
  57. 					directions[l] = RIGHT;
  58. 					last_left_going_right = l;
  59.  
  60. 				} else {
  61. 					directions[l] = NONE;
  62. 					--i;
  63. 					last_left_going_left = l;
  64. 				}
  65. 			}
  66. 		}
  67.  
  68. 		for (i = count, l = 0, r = length; l <= length && r >= 0; ++l, --r) {
  69. 			if (directions[r] == LEFT) {
  70. 				last_right_going_left = r;
  71.  
  72. 			} else if (directions[r] == RIGHT) {
  73. 				if (last_right_going_left > r) {
  74. 					directions[last_right_going_left] = NONE;
  75. 					--i;
  76. 					last_right_going_right = last_right_going_left;
  77. 					directions[l] = LEFT;
  78. 					last_right_going_left = r;
  79.  
  80. 				} else {
  81. 					directions[r] = NONE;
  82. 					--i;
  83. 					last_right_going_right = r;
  84. 				}
  85. 			}
  86. 		}
  87.  
  88. 		printf("The last ant will fall down in %d seconds - started at ", max_time);
  89.  
  90. 		i = 0;
  91.  
  92. 		if (last_left_going_right != length + 1) {
  93. 			posibilities[i] = last_left_going_right;
  94. 			posibilities_directions[i] = RIGHT;
  95. 			++i;
  96. 		}
  97.  
  98. 		if (last_left_going_left >= 0) {
  99. 			posibilities[i] = last_left_going_left;
  100. 			posibilities_directions[i] = LEFT;
  101. 			++i;
  102. 		}
  103.  
  104. 		if (last_right_going_left >= 0) {
  105. 			posibilities[i] = last_right_going_left;
  106. 			posibilities_directions[i] = LEFT;
  107. 			++i;
  108. 		}
  109.  
  110. 		if (last_right_going_right >= 0) {
  111. 			posibilities[i] = last_right_going_right;
  112. 			posibilities_directions[i] = RIGHT;
  113. 			++i;
  114. 		}
  115.  
  116. 		max = max2 = -1;
  117. 		pos = pos2 = -1;
  118. 		i -= 1;
  119.  
  120. 		while (i >= 0) {
  121. 			//printf("[%d] = %d %c\n", i, posibilities[i], posibilities_directions[i]);
  122. 			time = falltime(posibilities[i], posibilities_directions[i], length);
  123. 			if (time >= max) {
  124. 				//printf("max is %d\n", posibilities[i]);
  125. 				max2 = max;
  126. 				pos2 = pos;
  127. 				max = time;
  128. 				pos = posibilities[i];
  129. 			}
  130. 			--i;
  131. 		}
  132.  
  133. 		if (max == max2 && pos != pos2) {
  134. 			if (pos < pos2) {
  135. 				printf("%d and %d.\n", pos, pos2);
  136. 			} else {
  137. 				printf("%d and %d.\n", pos2, pos);
  138. 			}
  139. 		} else {
  140. 			printf("%d.\n", pos);
  141. 		}
  142. 	}
  143.  
  144. 	return 0;
  145. }
  146.  

Diff to submission s958

ants.c

--- c4.s958.cteam044.ants.c.0.ants.c
+++ c4.s1224.cteam044.ants.c.0.ants.c
@@ -64,5 +64,7 @@
                                 }
                         }
+                }
 
+                for (i = count, l = 0, r = length; l <= length && r >= 0; ++l, --r) {
                         if (directions[r] == LEFT) {
                                 last_right_going_left = r;