#!/usr/bin/env python3

#      N
#   NW   NO
# W    X    O
#   SW   SO
#      S

from collections import defaultdict
import math

freqmap = defaultdict(list)
lx = 0
ly = 0

with open("day08") as f:
    for y,l in enumerate(f):
        ly += 1
        lx = len(l.strip())
        for x,c in enumerate(l.strip()):
            if c != '.':
                freqmap[c].append((y,x))

antinodes = set()

for (_, coords) in freqmap.items():
    for s,a in enumerate(coords):
        for b in coords[s+1:]:
            dy = abs(a[0]-b[0])
            dx = abs(a[1]-b[1])

            # vertical
            if a[1]==b[1] and a[0]<b[0]:
                    antinodes.add((a[0]-dy,a[1]))
                    antinodes.add((b[0]+dy,b[1]))
            if a[1]==b[1] and a[0]>b[0]:
                    antinodes.add((a[0]+dy,a[1]))
                    antinodes.add((b[0]-dy,b[1]))

            # horizontal
            if a[0]==b[0] and a[1]<b[1]:
                    antinodes.add((a[0],a[1]-dx))
                    antinodes.add((b[0],b[1]+dx))
            if a[0]==b[0] and a[1]>b[1]:
                    antinodes.add((a[0],a[1]+dx))
                    antinodes.add((b[0],b[1]-dx))

            # positive slope
            if a[0]<b[0] and a[1]<b[1]:
                antinodes.add((a[0]-dy,a[1]-dx))
                antinodes.add((b[0]+dy,b[1]+dx))
            if a[0]>b[0] and a[1]>b[1]:
                antinodes.add((a[0]+dy,a[1]+dx))
                antinodes.add((b[0]-dy,b[1]-dx))

            # negative slope
            if a[0]<b[0] and a[1]>b[1]:
                antinodes.add((a[0]-dy,a[1]+dx))
                antinodes.add((b[0]+dy,b[1]-dx))
            if a[0]>b[0] and a[1]<b[1]:
                antinodes.add((a[0]+dy,a[1]-dx))
                antinodes.add((b[0]-dy,b[1]+dx))


def boundscheck(antinode):
    if antinode[0] < 0: return False
    if antinode[0] >= ly: return False
    if antinode[1] < 0: return False
    if antinode[1] >= lx: return False

    return True

def printmap():
    with open("day08") as f:
        for y,l in enumerate(f):
            for x,c in enumerate(l):
                if c == '.':
                    if (y,x) in antinodes2:
                        print("#", end=" ")
                    else: print(".", end=" ")
                else:
                    print(c.strip(), end=" ")
            print()

res = len({antinode for antinode in antinodes if boundscheck(antinode)})

# 2

antinodes2 = set()

for (_, coords) in freqmap.items():
    for s,a in enumerate(coords):
        for b in coords[s+1:]:
            slope = ((a[0]-b[0]) / (a[1]-b[1]))
            # y = mx + y0
            y0 = a[0] - slope*a[1]

            for x in range(lx):
                y = (slope*x)+y0
                if abs(round(y)-y) < 0.0001:
                    antinodes2.add((int(round(y)), x))


res2 = len({antinode for antinode in antinodes2 if boundscheck(antinode)})