commit 2cd8129387019cd02e58cc2fb6c774b059f2588e
parent fefd390804d34ac89197d30d464e427df833a85b
Author: bsandro <email@bsandro.tech>
Date: Sun, 8 Dec 2024 19:39:26 +0200
Day 08 p1
Diffstat:
4 files changed, 191 insertions(+), 0 deletions(-)
diff --git a/day08/Makefile b/day08/Makefile
@@ -0,0 +1,28 @@
+NAME=$(shell basename ${PWD})
+SRC=$(wildcard *.cpp)
+DEPS:=$(wildcard *.hpp)
+OBJ:=$(SRC:.cpp=.o)
+CXXFLAGS=-O2 -std=c++23 -Werror -Wall -Wextra -I.
+LDFLAGS=-lstdc++
+
+all: $(NAME)
+
+.PHONY: clean run
+
+clean:
+ rm -f $(OBJ) $(NAME)
+
+%.o : %.c $(DEPS)
+ @$(CC) $(CFLAGS) -c $< -o $@
+
+$(NAME): $(OBJ)
+ @$(CC) $(OBJ) -o $@ $(LDFLAGS)
+
+run: $(NAME)
+ @./$(NAME) input.txt
+
+test1: $(NAME)
+ @./$(NAME) test1.txt
+
+test2: $(NAME)
+ @./$(NAME) test2.txt
diff --git a/day08/input.txt b/day08/input.txt
@@ -0,0 +1,50 @@
+...............................s..................
+..................s..............q.............p..
+.....a............................................
+........c......Y.......Q..........................
+............................................4.....
+........Y.........y............m..........4.......
+......................Y...s..........S............
+.........................................S........
+...............N.............y....................
+...........a.......y..................1...........
+................................................S.
+...c........k.............q....t............S.....
+.............................qM...................
+........a.........................................
+..................................................
+..................................................
+..c..........k...Q..q....P........................
+5.................Q...................8...........
+......yc..........................................
+........................E............4............
+.........6........................u..p.....4......
+.........5.............P..n......1.........N......
+6..............................1.........J.t......
+..6..................................3.u..t.....p.
+....5...k..........................u..............
+.......................E..................u....x..
+..................E.................x.............
+...k..................P.............3.............
+...........0.....9.5...........E.........31e....N.
+......0.................................N.........
+.................CU.....................t....x....
+......7....................e......................
+....0..........K......C...........................
+.....6....j......M............................J...
+......K.................................p.........
+.....9........................U...................
+............................3....n................
+.............K.........2.....C..................x.
+....................P........UJ...................
+.....0......X...C.........T..............U........
+.......M.....8j....7.............2........Q.......
+9...............K.................................
+....e.....8.........................2.A.m.........
+..e......8.........s...n..........................
+.....................................T..nm........
+...................X............2.........m......A
+......................X..j....................T...
+.........7..M......j.............T................
+....9...7....................................A....
+..........................................A.......
diff --git a/day08/main.cpp b/day08/main.cpp
@@ -0,0 +1,101 @@
+#include <iostream>
+#include <filesystem>
+#include <fstream>
+#include <vector>
+#include <cstring>
+#include <cstdio>
+#include <tuple>
+#include <algorithm>
+#include <map>
+#include <set>
+
+typedef std::pair<int, int> Vec2;
+typedef std::map<char, std::vector<Vec2>> Data;
+
+// I got too lazy these days
+[[ maybe_unused ]] static int sFieldSize = 0;
+
+std::vector<Vec2> calc_an(Vec2 a1, Vec2 a2) {
+ std::vector<Vec2> out;
+ Vec2 d1(a1.first-a2.first, a1.second-a2.second);
+ Vec2 d2(-d1.first, -d1.second);
+ Vec2 p1(a1.first+d1.first, a1.second+d1.second);
+ Vec2 p2(a2.first+d2.first, a2.second+d2.second);
+ if (p1.first>=0&&p1.second>=0&&p1.first<sFieldSize&&p1.second<sFieldSize) {
+ out.push_back(p1);
+ }
+ if (p2.first>=0&&p2.second>=0&&p2.first<sFieldSize&&p2.second<sFieldSize) {
+ out.push_back(p2);
+ }
+ return out;
+}
+
+std::set<Vec2> calc_antinodes(const std::vector<Vec2> &antennas) {
+ std::set<Vec2> out;
+ for (auto it1=antennas.begin(); it1!=antennas.end(); it1++) {
+ for (auto it2=it1+1; it2!=antennas.end(); it2++) {
+ auto [x1, y1] = *it1;
+ auto [x2, y2] = *it2;
+ std::printf("%d:%d -> %d:%d\n", x1, y1, x2, y2);
+ std::vector<Vec2> an = calc_an(*it1, *it2);
+ for (auto &v:an) out.insert(v);
+ }
+ }
+ return out;
+}
+
+template<typename T>
+T read_file(const std::string &path) {
+ std::ifstream ifs(path, std::ios::binary);
+ if (!ifs.is_open()) {
+ throw std::runtime_error(path+":"+std::strerror(errno));
+ }
+ T buf;
+ int y=0;
+ while (1) {
+ std::string str;
+ std::getline(ifs, str);
+ if (!str.empty()) {
+ for (int x=0; x<(int)str.size(); ++x) {
+ if (str[x]!='.') buf[str[x]].push_back(Vec2(x, y));
+ }
+ }
+ ++y;
+ if (!ifs) break;
+ }
+ sFieldSize = y-1;
+ return buf;
+}
+
+int part1(Data &input [[ maybe_unused ]]) {
+ std::set<Vec2> out;
+ std::cout << std::endl;
+ for (auto &[k, v] : input) {
+ std::cout << "key:" << k << std::endl;
+ for (auto &p : v) {
+ std::cout << "[" << p.first << "," << p.second << "]";
+ }
+ std::cout << std::endl;
+ std::set<Vec2> an = calc_antinodes(v);
+ std::printf("%ld antinodes:", an.size());
+ for (auto &n:an) {
+ std::printf("[%d,%d]", n.first, n.second);
+ out.insert(n);
+ }
+ std::cout << std::endl;
+ }
+ return (int)out.size();
+}
+int part2(Data &input [[ maybe_unused ]]) {
+ return 0;
+}
+
+int main(int argc, char **argv) {
+ const std::string fname = argc>1 ? argv[1] : "test1.txt";
+ std::cout << "AoC 2024 day 08 " << fname << std::endl;
+ Data input = read_file<Data>(fname);
+ std::cout << "part1: " << part1(input) << std::endl;
+ std::cout << "part2: " << part2(input) << std::endl;
+
+ return 0;
+}
diff --git a/day08/test1.txt b/day08/test1.txt
@@ -0,0 +1,12 @@
+............
+........0...
+.....0......
+.......0....
+....0.......
+......A.....
+............
+............
+........A...
+.........A..
+............
+............
