misc/HexGrid.h

• View this file on GitHub
• Last update: 2025-11-14 00:13:37+07:00

Code

int roundCount(int round) { return (6 * round); }
int roundSum(int round) { return (6 * round * (round + 1) / 2); }
int findRound(int n) {
  int res = 1;
  while (roundSum(res) < n) res++;
  return (res);
}
pair<int, int> cord(int n) {
  if (n == 0) return (make_pair(0, 0));
  int c = findRound(n);
  int prev = roundSum(c - 1);
  if (n <= prev + c) return (make_pair(c, n - prev));
  if (n <= prev + 2 * c) return (make_pair(prev + 2 * c - n, c));
  if (n <= prev + 3 * c) return (make_pair(prev + 2 * c - n, prev + 3 * c - n));
  if (n <= prev + 4 * c) return (make_pair(-c, prev + 3 * c - n));
  if (n <= prev + 5 * c) return (make_pair(n - prev - 5 * c, -c));
  return (make_pair(n - prev - 5 * c, n - prev - 6 * c));
}
bool inRound(int x, int y, int c) {
  if (0 <= y && y <= c && x == c) return (true);
  if (0 <= x && x <= c && y == c) return (true);
  if (0 <= y && y <= c && y - x == c) return (true);
  if (-c <= y && y <= 0 && x == -c) return (true);
  if (-c <= x && x <= 0 && y == -c) return (true);
  if (0 <= x && x <= c && x - y == c) return (true);
  return (false);
}
int findRound(int x, int y) {
  int res = 1;
  while (!inRound(x, y, res)) res++;
  return (res);
}
int number(int x, int y) {
  if (x == 0 && y == 0) return (0);
  int c = findRound(x, y);
  int prev = roundSum(c - 1);
  if (1 <= y && y <= c && x == c) return (prev + y);
  if (0 <= x && x <= c && y == c) return (prev + 2 * c - x);
  if (0 <= y && y <= c && y - x == c) return (prev + 2 * c - x);
  if (-c <= y && y <= 0 && x == -c) return (prev + 3 * c - y);
  if (-c <= x && x <= 0 && y == -c) return (prev + 5 * c + x);
  return (prev + 5 * c + x);
}

#line 1 "misc/HexGrid.h"
int roundCount(int round) { return (6 * round); }
int roundSum(int round) { return (6 * round * (round + 1) / 2); }
int findRound(int n) {
  int res = 1;
  while (roundSum(res) < n) res++;
  return (res);
}
pair<int, int> cord(int n) {
  if (n == 0) return (make_pair(0, 0));
  int c = findRound(n);
  int prev = roundSum(c - 1);
  if (n <= prev + c) return (make_pair(c, n - prev));
  if (n <= prev + 2 * c) return (make_pair(prev + 2 * c - n, c));
  if (n <= prev + 3 * c) return (make_pair(prev + 2 * c - n, prev + 3 * c - n));
  if (n <= prev + 4 * c) return (make_pair(-c, prev + 3 * c - n));
  if (n <= prev + 5 * c) return (make_pair(n - prev - 5 * c, -c));
  return (make_pair(n - prev - 5 * c, n - prev - 6 * c));
}
bool inRound(int x, int y, int c) {
  if (0 <= y && y <= c && x == c) return (true);
  if (0 <= x && x <= c && y == c) return (true);
  if (0 <= y && y <= c && y - x == c) return (true);
  if (-c <= y && y <= 0 && x == -c) return (true);
  if (-c <= x && x <= 0 && y == -c) return (true);
  if (0 <= x && x <= c && x - y == c) return (true);
  return (false);
}
int findRound(int x, int y) {
  int res = 1;
  while (!inRound(x, y, res)) res++;
  return (res);
}
int number(int x, int y) {
  if (x == 0 && y == 0) return (0);
  int c = findRound(x, y);
  int prev = roundSum(c - 1);
  if (1 <= y && y <= c && x == c) return (prev + y);
  if (0 <= x && x <= c && y == c) return (prev + 2 * c - x);
  if (0 <= y && y <= c && y - x == c) return (prev + 2 * c - x);
  if (-c <= y && y <= 0 && x == -c) return (prev + 3 * c - y);
  if (-c <= x && x <= 0 && y == -c) return (prev + 5 * c + x);
  return (prev + 5 * c + x);
}

Back to top page