Add day 19 solution

day-19/day-19.py

@@ -0,0 +1,165 @@
+#!/usr/bin/env python3
+from pathlib import Path
+
+
+def parse(input):
+    scanners = []
+    s = []
+    for line in input:
+        line = line.rstrip()
+        if 'scanner' in line:
+            s = []
+            continue
+        if len(line):
+            b = tuple([int(x) for x in line.split(',')])
+            s.append(b)
+        else:
+            scanners.append(s)
+    if len(s):
+        scanners.append(s)
+    return scanners
+
+
+def calc_distances(s):
+    d = []
+    for _ in s:
+        d.append(set())
+    for i in range(len(s)):
+        for j in range(i+1, len(s)):
+            dist = 0
+            for k in range(len(s[i])):
+                dist += (s[i][k] - s[j][k]) ** 2
+            d[i].add(dist)
+            d[j].add(dist)
+    return d
+
+
+def num_overlapping(s0, s1):
+    num = 0
+    for b0 in s0:
+        for b1 in s1:
+            if 11 <= len(b0 & b1):
+                num += 1
+    return num
+
+
+def get_transform_func(v0, v1):
+    (x0, y0, z0) = v0
+    (x1, y1, z1) = v1
+    transform = '('
+    if abs(x0) == abs(x1):
+        if 0 > x0 // x1:
+            transform += '-'
+        transform += 'x,'
+    elif abs(x0) == abs(y1):
+        if 0 > x0 // y1:
+            transform += '-'
+        transform += 'y,'
+    elif abs(x0) == abs(z1):
+        if 0 > x0 // z1:
+            transform += '-'
+        transform += 'z,'
+    if abs(y0) == abs(x1):
+        if 0 > y0 // x1:
+            transform += '-'
+        transform += 'x,'
+    elif abs(y0) == abs(y1):
+        if 0 > y0 // y1:
+            transform += '-'
+        transform += 'y,'
+    elif abs(y0) == abs(z1):
+        if 0 > y0 // z1:
+            transform += '-'
+        transform += 'z,'
+    if abs(z0) == abs(x1):
+        if 0 > z0 // x1:
+            transform += '-'
+        transform += 'x'
+    elif abs(z0) == abs(y1):
+        if 0 > z0 // y1:
+            transform += '-'
+        transform += 'y'
+    elif abs(z0) == abs(z1):
+        if 0 > z0 // z1:
+            transform += '-'
+        transform += 'z'
+    transform += ')'
+    return transform
+
+
+def transform(scanners, idx, done=[]):
+    done.append(idx)
+    for n in scanners[idx]['overlapping']:
+        if n in done:
+            continue
+        overlapping = []
+        for i, b0 in enumerate(scanners[idx]['metrics']):
+            for j, b1 in enumerate(scanners[n]['metrics']):
+                if 11 <= len(b0 & b1):
+                    overlapping.append((i, j))
+                if 2 <= len(overlapping):
+                    break
+            if 2 <= len(overlapping):
+                break
+        assert len(overlapping) == 2
+        (x0, y0, z0) = scanners[idx]['beacons'][overlapping[0][0]]
+        (x1, y1, z1) = scanners[idx]['beacons'][overlapping[1][0]]
+        v0 = (x0 - x1, y0 - y1, z0 - z1)
+        (x0, y0, z0) = scanners[n]['beacons'][overlapping[0][1]]
+        (x1, y1, z1) = scanners[n]['beacons'][overlapping[1][1]]
+        v1 = (x0 - x1, y0 - y1, z0 - z1)
+        transform_func = get_transform_func(v0, v1)
+        for i in range(len(scanners[n]['beacons'])):
+            (x, y, z) = scanners[n]['beacons'][i]
+            scanners[n]['beacons'][i] = eval(transform_func)
+        (xo, yo, zo) = scanners[idx]['origin']
+        (x0, y0, z0) = scanners[idx]['beacons'][overlapping[0][0]]
+        (x1, y1, z1) = scanners[n]['beacons'][overlapping[0][1]]
+        scanners[n]['origin'] = (xo + x0 - x1, yo + y0 - y1, zo + z0 - z1)
+        (xo, yo, zo) = scanners[n]['origin']
+        transform(scanners, n, done)
+        for i in range(len(scanners[n]['beacons'])):
+            (x, y, z) = scanners[n]['beacons'][i]
+            scanners[n]['beacons'][i] = (x + xo, y + yo, z + zo)
+
+
+def solve(input):
+    result_p1 = 0
+    result_p2 = 0
+    beacons = parse(input)
+    scanners = []
+    for b in beacons:
+        s = {}
+        s['beacons'] = b
+        s['metrics'] = calc_distances(b)
+        s['origin'] = (0, 0, 0)
+        s['overlapping'] = []
+        scanners.append(s)
+    for i in range(len(scanners)):
+        for j in range(i + 1, len(scanners)):
+            num = num_overlapping(
+                scanners[i]['metrics'], scanners[j]['metrics'])
+            if num:
+                scanners[i]['overlapping'].append(j)
+                scanners[j]['overlapping'].append(i)
+    transform(scanners, 0)
+    m = set()
+    for s in scanners:
+        for b in s['beacons']:
+            m.add(b)
+    result_p1 = len(m)
+    for i in range(len(scanners)):
+        (xi, yi, zi) = scanners[i]['origin']
+        for j in range(i + 1, len(scanners)):
+            (xj, yj, zj) = scanners[j]['origin']
+            md = abs(xi - xj) + abs(yi - yj) + abs(zi - zj)
+            result_p2 = max(result_p2, md)
+    print("Part 1 result:", result_p1)
+    print("Part 2 result:", result_p2)
+
+
+input = list()
+p = Path(__file__).with_name('input.txt')
+with open(p) as f:
+    input = f.readlines()
+    solve(input)