05a.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <stdbool.h>
   4
   5 struct line { int x1; int y1; int x2; int y2; };
   6
   7 #define max(x, y) ((x)>(y) ? (x) : (y))
   8 #define min(x, y) ((x)<(y) ? (x) : (y))
   9 #define between(a, a1, a2) ((a) >= min(a1, a2) && (a) <= max(a1, a2))
  10
  11 int parse_lines(struct line lines[], int *maxx, int *maxy)
  12 {
  13         int i = 0;
  14         char buf[1000];
  15         while (fgets(buf, 1000, stdin) != NULL) {
  16                 char *p = &buf[0];
  17                 lines[i].x1 = strtol(p, &p, 10);
  18                 p++;
  19                 lines[i].y1 = strtol(p, &p, 10);
  20                 p+=4;
  21                 lines[i].x2 = strtol(p, &p, 10);
  22                 p++;
  23                 lines[i].y2 = strtol(p, &p, 10);
  24                 *maxx = max(*maxx, lines[i].x1);
  25                 *maxx = max(*maxx, lines[i].x2);
  26                 *maxy = max(*maxy, lines[i].y1);
  27                 *maxy = max(*maxy, lines[i].y2);
  28                 i++;
  29         }
  30         return i;
  31 }
  32
  33 bool online(int x, int y, struct line line)
  34 {
  35         //Vertical
  36         if (line.x1 == line.x2 && x == line.x1)
  37                 return between(y, line.y1, line.y2);
  38         //Horizontal
  39         if (line.y1 == line.y2 && y == line.y2)
  40                 return between(x, line.x1, line.x2);
  41         return false;
  42 }
  43
  44 int main()
  45 {
  46         struct line lines[1000];
  47         int maxx = 0, maxy = 0;
  48         int nlines = parse_lines(lines, &maxx, &maxy);
  49         int r = 0;
  50         for (int x = 0; x<=maxx; x++) {
  51                 for (int y = 0; y<=maxy; y++) {
  52                         int matches = 0;
  53                         for (int line = 0; line<nlines && matches < 2; line++)
  54                                 if (online(x, y, lines[line]))
  55                                         matches++;
  56                         r = matches >= 2 ? r+1 : r;
  57                 }
  58         }
  59         printf("%d\n", r);
  60 }