05a.c

   1 #include <stdio.h>
   2 #include <uthash.h>
   3
   4 #define SWAP(x, y) { x ^= y; y ^= x; x ^= y; }
   5
   6 struct point { int x; int y; };
   7 struct entry { struct point key; int i; UT_hash_handle hh; };
   8
   9 void mark_point(int x, int y, struct entry **entries, int *r)
  10 {
  11         struct entry *p;
  12         struct point s = { .x=x, .y=y };
  13         HASH_FIND(hh, *entries, &s, sizeof(struct point), p);
  14         if (p) {
  15                 if (p->i++ == 1)
  16                         *r = *r+1;
  17         } else {
  18                 p = malloc(sizeof(struct entry));
  19                 p->key = s;
  20                 p->i = 1;
  21                 HASH_ADD(hh, *entries, key, sizeof(struct point), p);
  22         }
  23 }
  24
  25 int main()
  26 {
  27         char buf[1000];
  28         struct entry *entries = NULL;
  29         int r = 0;
  30         while (fgets(buf, 1000, stdin) != NULL) {
  31                 char *ptr = &buf[0];
  32                 int x1 = strtol(ptr, &ptr, 10);
  33                 ptr++;
  34                 int y1 = strtol(ptr, &ptr, 10);
  35                 ptr+=4;
  36                 int x2 = strtol(ptr, &ptr, 10);
  37                 ptr++;
  38                 int y2 = strtol(ptr, &ptr, 10);
  39                 if (x1 > x2)
  40                         SWAP(x1, x2);
  41                 if (y1 > y2)
  42                         SWAP(y1, y2);
  43
  44                 //Vertical
  45                 if (x1 == x2)
  46                         for (int y = y1; y<=y2; y++)
  47                                 mark_point(x1, y, &entries, &r);
  48                 //Horizontal
  49                 else if (y1 == y2)
  50                         for (int x = x1; x<=x2; x++)
  51                                 mark_point(x, y1, &entries, &r);
  52         }
  53         printf("%d\n", r);
  54 }