17b.c

   1 #include <stdio.h>
   2 #include <stdbool.h>
   3
   4 bool is_in(int dx, int dy, int x1, int x2, int y1, int y2)
   5 {
   6         int x = 0, y = 0;
   7         while (y >= y1 && x <= x2) {
   8                 x+=dx;
   9                 y+=dy;
  10                 dx = dx == 0 ? 0 : dx-1;
  11                 dy--;
  12                 if (x >= x1 && x <= x2 && y >= y1 && y <= y2)
  13                         return true;
  14         }
  15         return false;
  16 }
  17
  18 int main()
  19 {
  20         int x1, x2, y1, y2, n = 0;
  21         scanf("target area: x=%d..%d, y=%d..%d\n", &x1, &x2, &y1, &y2);
  22         for (int dy = x2; dy >= y1; dy--)
  23                 for (int dx = 0; dx <= x2; dx++)
  24                         if (is_in(dx, dy, x1, x2, y1, y2))
  25                                 n++;
  26         printf("%d\n", n);
  27 }