commit e819cc8bb54f51d1be2e65984da7bbbef204e79f
parent 0707d69626781fad2f435f8827b3796e1f8b9898
Author: bsandro <email@bsandro.tech>
Date: Tue, 17 Dec 2024 08:39:31 +0200
Day 17 p1
Diffstat:
4 files changed, 161 insertions(+), 0 deletions(-)
diff --git a/day17/Makefile b/day17/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. -I../include
+LDFLAGS=-lstdc++ -lm
+
+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/day17/input.txt b/day17/input.txt
@@ -0,0 +1,5 @@
+Register A: 30886132
+Register B: 0
+Register C: 0
+
+Program: 2,4,1,1,7,5,0,3,1,4,4,4,5,5,3,0
diff --git a/day17/main.cpp b/day17/main.cpp
@@ -0,0 +1,123 @@
+#include <iostream>
+#include <filesystem>
+#include <fstream>
+#include <vector>
+#include <cstring>
+#include <cstdio>
+#include <tuple>
+#include <algorithm>
+#include <cmath>
+#include "utils.hpp"
+
+typedef std::vector<std::pair<int, int>> Data;
+
+class Cpu {
+public:
+// instruction pointer
+ int ip = 0;
+// registers
+ int a = 0;
+ int b = 0;
+ int c = 0;
+// combo operand
+ int combo(int o) {
+ if (o>=0&&o<=3) return o;
+ if (o==4) return a;
+ if (o==5) return b;
+ if (o==6) return c;
+ std::printf("invalid combo operand %d\n", o);
+ return 0;
+ }
+// opcodes 0-7
+ int adv(int o) { a /= std::pow(2, combo(o)); return ++ip; }
+ int bxl(int o) { b ^= o; return ++ip; };
+ int bst(int o) { b = combo(o) % 8; return ++ip; };
+ int jnz(int o) { if (a==0) ip++; else ip=o; return ip; };
+ int bxc(int o [[maybe_unused]]) { b ^= c; return ++ip; };
+ int out(int o, std::stringstream &ss) { ss << (combo(o)%8) << ","; return ++ip; };
+ int bdv(int o) { b = a/std::pow(2, combo(o)); return ++ip; };
+ int cdv(int o) { c = a/std::pow(2, combo(o)); return ++ip; };
+// main thing
+ int eval(int op, int o, std::stringstream &ss);
+ std::string run(const Data &input);
+ void print() { std::printf("ip:%d,a:%d,b:%d,c:%d\n", ip, a, b, c); }
+};
+
+int Cpu::eval(int op, int o, std::stringstream &ss) {
+ switch (op) {
+ case 0: return adv(o);
+ case 1: return bxl(o);
+ case 2: return bst(o);
+ case 3: return jnz(o);
+ case 4: return bxc(o);
+ case 5: return out(o, ss);
+ case 6: return bdv(o);
+ case 7: return cdv(o);
+ }
+ std::printf("invalid opcode\n");
+ return -1;
+}
+
+std::string Cpu::run(const Data &input) {
+ std::stringstream ss;
+ while (ip>=0&&ip<(int)input.size()) ip=eval(input[ip].first, input[ip].second, ss);
+ return ss.str();
+}
+
+std::tuple<Cpu, Data> 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));
+ }
+ Data buf;
+ Cpu cpu;
+ for (int l=0;;l++) {
+ std::string str;
+ std::getline(ifs, str);
+ if (!str.empty()) {
+ if (l==0) std::sscanf(str.c_str(), "Register A: %d", &cpu.a);
+ if (l==1) std::sscanf(str.c_str(), "Register B: %d", &cpu.b);
+ if (l==2) std::sscanf(str.c_str(), "Register C: %d", &cpu.c);
+ if (l==4) {
+ char tmp[256] = {0};
+ std::sscanf(str.c_str(), "Program: %[^\n]", tmp);
+ std::istringstream iss(tmp);
+ std::pair<int,int> instr;
+ int num = 0;
+ for (std::string sn; std::getline(iss, sn, ',');) {
+ if (num%2==0) {
+ instr.first = std::stoi(sn);
+ } else {
+ instr.second = std::stoi(sn);
+ buf.push_back(instr);
+ }
+ num++;
+ }
+ }
+ }
+ if (!ifs) break;
+ }
+ return std::make_pair(cpu, buf);
+}
+
+std::string part1(Cpu cpu [[ maybe_unused ]], Data input [[ maybe_unused ]]) {
+ //cpu.print();
+ //for (auto [opcode, operand] : input) std::printf("[%d,%d]", opcode, operand);
+
+ return cpu.run(input);
+}
+
+int64_t part2(Data &input [[ maybe_unused ]]) {
+ return 0;
+}
+
+int main(int argc, char **argv) {
+ Performance perf;
+ const std::string fname = argc>1 ? argv[1] : "test1.txt";
+ std::cout << "AoC 2024 day 17 " << fname << std::endl;
+ auto [cpu, input] = read_file(fname);
+ std::cout << "part1: " << part1(cpu, input) << std::endl;
+ std::cout << "part2: " << part2(input) << std::endl;
+
+ return 0;
+}
diff --git a/day17/test1.txt b/day17/test1.txt
@@ -0,0 +1,5 @@
+Register A: 729
+Register B: 0
+Register C: 0
+
+Program: 0,1,5,4,3,0
