commit e2a90aab7febe9ca73661d17a26fcb0dd10a68a7
parent d9fbaa155185220ee141f75d764890983ef35ca2
Author: Sebastiano Tronto <sebastiano@tronto.net>
Date: Sun, 15 Dec 2024 09:05:08 +0100
Day 15 2024
Diffstat:
3 files changed, 367 insertions(+), 0 deletions(-)
diff --git a/2024/15/Makefile b/2024/15/Makefile
@@ -0,0 +1,24 @@
+CC=g++ -std=c++20 -g -Wall
+
+a:
+ ${CC} -o a.out day15a.cpp
+
+b:
+ ${CC} -o b.out day15b.cpp
+
+clean:
+ rm -f a b
+
+atest: a
+ ./a.out
+
+btest: b
+ ./b.out
+
+arun: a
+ ./a.out < input
+
+brun: b
+ ./b.out < input
+
+.PHONY: a b clean atest btest arun brun
diff --git a/2024/15/day15a.cpp b/2024/15/day15a.cpp
@@ -0,0 +1,141 @@
+#include <iostream>
+#include <cstdint>
+#include <algorithm>
+#include <string>
+#include <string_view>
+#include <vector>
+#include <set>
+using namespace std;
+
+class Direction {
+public:
+ const int U, R;
+
+ Direction(char c) :
+ U{c == 'v' ? 1 : (c == '^' ? -1 : 0)},
+ R{c == '>' ? 1 : (c == '<' ? -1 : 0)} {}
+
+ Direction(const int i, const int j) : U{i}, R{j} {}
+
+ Direction turnright() const {
+ return turn(-1, 0);
+ }
+
+ Direction turnleft() const {
+ return turn(1, 0);
+ }
+
+ bool operator<(const Direction& d) const { // For set<Direction>
+ return this->U < d.U || (this->U == d.U && this->R < d.R);
+ }
+private:
+ Direction turn(int64_t sin, int64_t cos) const {
+ return Direction(cos * U - sin * R, sin * U + cos * R);
+ }
+};
+
+class Position {
+public:
+ int64_t i, j;
+
+ Position() : Position(0, 0) {}
+
+ Position(int64_t a, int64_t b) : i{a}, j{b} {}
+
+ Position step(const Direction d) const {
+ return Position(i+d.U, j+d.R);
+ }
+};
+
+const Direction all_directions[] = {
+ Direction(1, 0), Direction(-1, 0), Direction(0, 1), Direction(0, -1)
+};
+
+class Board {
+public:
+ int64_t N, M;
+ Position robot;
+
+ Board(const vector<string>& lines) :
+ N{static_cast<int64_t>(lines.size())},
+ M{static_cast<int64_t>(lines[0].size())},
+ cells(M*N)
+ {
+ for (int64_t i = 0; i < N; i++) {
+ for (int64_t j = 0; j < M; j++) {
+ cells[N*i+j] = lines[i][j];
+ if (lines[i][j] == '@')
+ robot = Position(i, j);
+ }
+ }
+ }
+
+ char& operator[](const Position p) {
+ if (const auto c = coord(p); c == -1)
+ return out_of_bound;
+ else
+ return cells[c];
+ }
+
+ void move_robot(const Direction d) {
+ if (move(robot, d))
+ robot = robot.step(d);
+ }
+
+ int64_t gps() {
+ int64_t tot = 0;
+ for (Position p(0, 0); p.i < N; p.i++)
+ for (p.j = 0; p.j < M; p.j++)
+ if ((*this)[p] == 'O')
+ tot += 100*p.i + p.j;
+ return tot;
+ }
+
+ void print() {
+ for (Position p(0, 0); p.i < N; p.i++) {
+ for (p.j = 0; p.j < M; p.j++)
+ cout << (*this)[p];
+ cout << endl;
+ }
+ }
+private:
+ char out_of_bound = '$';
+
+ vector<char> cells;
+
+ int64_t coord(const Position p) const {
+ auto [i, j] = p;
+ return i >= N || i < 0 || j >= M || j < 0 ? -1 : N * i + j;
+ }
+
+ bool move(Position p, Direction d) {
+ auto q = p.step(d);
+ switch ((*this)[q]) {
+ case '.':
+ (*this)[q] = (*this)[p];
+ (*this)[p] = '.';
+ return true;
+ case 'O':
+ return move(q, d) ? move(p, d) : false;
+ default:
+ return false;
+ }
+ }
+};
+
+int main() {
+ string line;
+ vector<string> lines;
+
+ for (getline(cin, line); line.size() > 0; getline(cin, line))
+ lines.push_back(line);
+ Board board(lines);
+
+ while (getline(cin, line))
+ for (const auto& c : line)
+ board.move_robot(Direction(c));
+
+ cout << board.gps() << endl;
+
+ return 0;
+}
diff --git a/2024/15/day15b.cpp b/2024/15/day15b.cpp
@@ -0,0 +1,202 @@
+/*
+The code here is not great, but I don't feel like cleaning it up
+*/
+
+#include <iostream>
+#include <cstdint>
+#include <algorithm>
+#include <string>
+#include <string_view>
+#include <vector>
+#include <set>
+using namespace std;
+
+class Direction {
+public:
+ const int U, R;
+
+ Direction(char c) :
+ U{c == 'v' ? 1 : (c == '^' ? -1 : 0)},
+ R{c == '>' ? 1 : (c == '<' ? -1 : 0)} {}
+
+ Direction(const int i, const int j) : U{i}, R{j} {}
+
+ Direction turnright() const {
+ return turn(-1, 0);
+ }
+
+ Direction turnleft() const {
+ return turn(1, 0);
+ }
+
+ bool operator<(const Direction& d) const { // For set<Direction>
+ return this->U < d.U || (this->U == d.U && this->R < d.R);
+ }
+private:
+ Direction turn(int64_t sin, int64_t cos) const {
+ return Direction(cos * U - sin * R, sin * U + cos * R);
+ }
+};
+
+class Position {
+public:
+ int64_t i, j;
+
+ Position() : Position(0, 0) {}
+
+ Position(int64_t a, int64_t b) : i{a}, j{b} {}
+
+ Position step(const Direction d) const {
+ return Position(i+d.U, j+d.R);
+ }
+};
+
+const Direction all_directions[] = {
+ Direction(1, 0), Direction(-1, 0), Direction(0, 1), Direction(0, -1)
+};
+
+class Board {
+public:
+ int64_t N, M;
+ Position robot;
+
+ Board(const vector<string>& lines) :
+ N{static_cast<int64_t>(lines.size())},
+ M{static_cast<int64_t>(lines[0].size())},
+ cells(M*N)
+ {
+ for (int64_t i = 0; i < N; i++) {
+ for (int64_t j = 0; j < M; j++) {
+ cells[M*i+j] = lines[i][j];
+ if (lines[i][j] == '@')
+ robot = Position(i, j);
+ }
+ }
+ }
+
+ char& operator[](const Position p) {
+ if (const auto c = coord(p); c == -1)
+ return out_of_bound;
+ else
+ return cells[c];
+ }
+
+ void move_robot(const Direction d) {
+ if (move(robot, d))
+ robot = robot.step(d);
+ }
+
+ int64_t gps() {
+ int64_t tot = 0;
+ for (Position p(0, 0); p.i < N; p.i++)
+ for (p.j = 0; p.j < M; p.j++)
+ if ((*this)[p] == '[')
+ tot += 100*p.i + p.j;
+ return tot;
+ }
+
+ void print() {
+ for (Position p(0, 0); p.i < N; p.i++) {
+ for (p.j = 0; p.j < M; p.j++)
+ cout << (*this)[p];
+ cout << endl;
+ }
+ }
+private:
+ char out_of_bound = '$';
+
+ vector<char> cells;
+
+ int64_t coord(const Position p) const {
+ auto [i, j] = p;
+ return i >= N || i < 0 || j >= M || j < 0 ? -1 : M * i + j;
+ }
+
+ bool move(Position p, Direction d) {
+ return d.U == 0 ? move_h(p, d) : move_v(p, d);
+ }
+
+ bool move_h(Position p, Direction d) {
+ auto q = p.step(d);
+ switch ((*this)[q]) {
+ case '.':
+ (*this)[q] = (*this)[p];
+ (*this)[p] = '.';
+ return true;
+ case '[':
+ case ']':
+ return move(q, d) ? move(p, d) : false;
+ default:
+ return false;
+ }
+ }
+
+ bool move_v(Position p, Direction d) {
+ if (!isfree_v(p, d))
+ return false;
+
+ auto q = p.step(d);
+ if ((*this)[q] == '[') {
+ move_v(q, d);
+ move_v(q.step(Direction('>')), d);
+ }
+ if ((*this)[q] == ']') {
+ move_v(q, d);
+ move_v(q.step(Direction('<')), d);
+ }
+ (*this)[q] = (*this)[p];
+ (*this)[p] = '.';
+ return true;
+ }
+
+ bool isfree_v(Position p, Direction d) {
+ auto q = p.step(d);
+ switch ((*this)[q]) {
+ case '.':
+ return true;
+ case ']':
+ return isfree_v(q, d) &&
+ isfree_v(q.step(Direction('<')), d);
+ case '[':
+ return isfree_v(q, d) &&
+ isfree_v(q.step(Direction('>')), d);
+ default:
+ return false;
+ }
+ if ((*this)[q] == '.')
+ return true;
+ }
+};
+
+int main() {
+ string line;
+ vector<string> lines;
+
+ for (getline(cin, line); line.size() > 0; getline(cin, line)) {
+ string wideline = "";
+ for (const auto& c : line) {
+ switch (c) {
+ case 'O':
+ wideline += "[]";
+ break;
+ case '@':
+ wideline += "@.";
+ break;
+ default:
+ wideline += c;
+ wideline += c;
+ break;
+ }
+ }
+ lines.push_back(wideline);
+ }
+ Board board(lines);
+
+ while (getline(cin, line))
+ for (const auto& c : line)
+ board.move_robot(Direction(c));
+
+ cout << board.gps() << endl;
+
+ return 0;
+}
