05a.c

   1 #include <stdio.h>
   2 #include <stdint.h>
   3 #include <uthash.h>
   4
   5 #define SWAP(x, y) { x ^= y; y ^= x; x ^= y; }
   6
   7 struct point { int x; int y; };
   8 struct entry { struct point key; int i; UT_hash_handle hh; };
   9
  10 void mark_point(int x, int y, struct entry **entries, int *r)
  11 {
  12         struct entry *p;
  13         struct point s;
  14         memset(&s, 0, sizeof s);
  15         s.x = x;
  16         s.y = y;
  17         HASH_FIND(hh, *entries, &s, sizeof(struct point), p);
  18         if (p) {
  19                 if (p->i++ == 1)
  20                         *r = *r+1;
  21         } else {
  22                 p = calloc(1, sizeof(struct entry));
  23                 p->key = s;
  24                 p->i = 1;
  25                 HASH_ADD(hh, *entries, key, sizeof(struct point), p);
  26         }
  27 }
  28
  29 int main()
  30 {
  31         char buf[1000];
  32         struct entry *entries = NULL;
  33         int r = 0;
  34         while (fgets(buf, 1000, stdin) != NULL) {
  35                 char *ptr = &buf[0];
  36                 int x1 = strtol(ptr, &ptr, 10);
  37                 ptr++;
  38                 int y1 = strtol(ptr, &ptr, 10);
  39                 ptr+=4;
  40                 int x2 = strtol(ptr, &ptr, 10);
  41                 ptr++;
  42                 int y2 = strtol(ptr, &ptr, 10);
  43                 if (x1 > x2)
  44                         SWAP(x1, x2);
  45                 if (y1 > y2)
  46                         SWAP(y1, y2);
  47
  48                 //Vertical
  49                 if (x1 == x2)
  50                         for (int y = y1; y<=y2; y++)
  51                                 mark_point(x1, y, &entries, &r);
  52                 //Horizontal
  53                 else if (y1 == y2)
  54                         for (int x = x1; x<=x2; x++)
  55                                 mark_point(x, y1, &entries, &r);
  56         }
  57         printf("%d\n", r);
  58 }