AOC2023: Implement day19 part 1

This commit is contained in:
Bananymous 2023-12-23 18:47:44 +02:00
parent a0200a7b10
commit 64323c51e6
4 changed files with 244 additions and 1 deletions

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@ -21,6 +21,7 @@ set(AOC2023_PROJECTS
day16 day16
day17 day17
day18 day18
day19
full full
) )

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@ -0,0 +1,22 @@
cmake_minimum_required(VERSION 3.26)
project(aoc2023_day19 CXX)
set(SOURCES
main.cpp
)
add_executable(aoc2023_day19 ${SOURCES})
target_compile_options(aoc2023_day19 PUBLIC -O2 -g)
target_link_libraries(aoc2023_day19 PUBLIC libc ban)
add_dependencies(aoc2023_day19 libc-install ban-install)
add_custom_target(aoc2023_day19-install
COMMAND ${CMAKE_COMMAND} -E copy ${CMAKE_CURRENT_BINARY_DIR}/aoc2023_day19 ${BANAN_AOC2023_BIN}/day19
DEPENDS aoc2023_day19
DEPENDS aoc2023_always
)
add_dependencies(aoc2023 aoc2023_day19)
add_dependencies(aoc2023-install aoc2023_day19-install)

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@ -0,0 +1,220 @@
#include <BAN/HashMap.h>
#include <BAN/HashSet.h>
#include <BAN/String.h>
#include <BAN/Vector.h>
#include <ctype.h>
#include <inttypes.h>
#include <stdio.h>
using i8 = int8_t;
using i16 = int16_t;
using i32 = int32_t;
using i64 = int64_t;
using u8 = uint8_t;
using u16 = uint16_t;
using u32 = uint32_t;
using u64 = uint64_t;
enum Variable { x, m, a, s };
enum class Comparison { Less, Greater, Always };
struct Rule
{
Variable operand1;
i64 operand2;
Comparison comparison;
BAN::String target;
};
using Workflows = BAN::HashMapUnstable<BAN::String, BAN::Vector<Rule>>;
struct Item
{
i64 values[4];
bool operator==(const Item& other) const
{
return memcmp(values, other.values, sizeof(values)) == 0;
}
};
struct ItemHash
{
BAN::hash_t operator()(const Item& item) const
{
return BAN::hash<u64>()(item.values[0]) ^
BAN::hash<u64>()(item.values[1]) ^
BAN::hash<u64>()(item.values[2]) ^
BAN::hash<u64>()(item.values[3]);
};
};
i64 parse_i64(BAN::StringView str)
{
i64 result = 0;
for (size_t i = 0; i < str.size() && isdigit(str[i]); i++)
result = (result * 10) + (str[i] - '0');
return result;
}
bool get_line(FILE* fp, BAN::String& out)
{
out.clear();
bool success = false;
char buffer[128];
while (fgets(buffer, sizeof(buffer), fp))
{
success = true;
MUST(out.append(buffer));
if (out.back() == '\n')
{
out.pop_back();
break;
}
}
return success;
}
Workflows parse_workflows(FILE* fp)
{
Workflows workflows;
BAN::String line;
while (get_line(fp, line) && !line.empty())
{
auto name = line.sv().substring(0, *line.sv().find('{'));
MUST(workflows.emplace(name));
auto rule_str = line.sv().substring(*line.sv().find('{') + 1);
rule_str = rule_str.substring(0, rule_str.size() - 1);
auto rules_str = MUST(rule_str.split(','));
for (size_t i = 0; i < rules_str.size() - 1; i++)
{
Rule rule;
rule.operand1 = (rules_str[i][0] == 'x') ? Variable::x :
(rules_str[i][0] == 'm') ? Variable::m :
(rules_str[i][0] == 'a') ? Variable::a :
Variable::s;
rule.operand2 = parse_i64(rules_str[i].substring(2));
rule.comparison = (rules_str[i][1] == '<') ? Comparison::Less : Comparison::Greater;
rule.target = rules_str[i].substring(*rules_str[i].find(':') + 1);
MUST(workflows[name].push_back(BAN::move(rule)));
}
MUST(workflows[name].emplace_back(Variable::x, 0, Comparison::Always, rules_str.back()));
}
return workflows;
}
BAN::Vector<Item> parse_items(FILE* fp)
{
BAN::Vector<Item> items;
BAN::String line;
while (get_line(fp, line) && !line.empty())
{
auto values = MUST(line.sv().substring(1, line.size() - 2).split(','));
ASSERT(values.size() == 4);
ASSERT(values[0][0] == 'x');
ASSERT(values[1][0] == 'm');
ASSERT(values[2][0] == 'a');
ASSERT(values[3][0] == 's');
Item item;
item.values[0] = parse_i64(values[0].substring(2));
item.values[1] = parse_i64(values[1].substring(2));
item.values[2] = parse_i64(values[2].substring(2));
item.values[3] = parse_i64(values[3].substring(2));
MUST(items.push_back(item));
}
return items;
}
bool satifies_rule(const Item& item, const Rule& rule)
{
switch (rule.comparison)
{
case Comparison::Always:
return true;
case Comparison::Less:
return item.values[rule.operand1] < rule.operand2;
case Comparison::Greater:
return item.values[rule.operand1] > rule.operand2;
}
ASSERT_NOT_REACHED();
}
bool is_accepted(const Item& item, const BAN::String& name, const Workflows& workflows)
{
const auto& workflow = workflows[name];
for (const auto& rule : workflow)
{
if (!satifies_rule(item, rule))
continue;
if (rule.target == "A"sv)
return true;
if (rule.target == "R"sv)
return false;
return is_accepted(item, rule.target, workflows);
}
ASSERT_NOT_REACHED();
}
i64 puzzle1(FILE* fp)
{
auto workflows = parse_workflows(fp);
auto items = parse_items(fp);
BAN::Vector<Item> accepted;
for (const auto& item : items)
if (is_accepted(item, "in"sv, workflows))
MUST(accepted.push_back(item));
i64 result = 0;
for (const auto& item : accepted)
result += item.values[0] + item.values[1] + item.values[2] + item.values[3];
return result;
}
i64 puzzle2(FILE* fp)
{
(void)fp;
return -1;
}
int main(int argc, char** argv)
{
const char* file_path = "/usr/share/aoc2023/day19_input.txt";
if (argc >= 2)
file_path = argv[1];
FILE* fp = fopen(file_path, "r");
if (fp == nullptr)
{
perror("fopen");
return 1;
}
printf("puzzle1: %" PRId64 "\n", puzzle1(fp));
fseek(fp, 0, SEEK_SET);
printf("puzzle2: %" PRId64 "\n", puzzle2(fp));
fclose(fp);
}

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@ -4,7 +4,7 @@
int main() int main()
{ {
for (int i = 1; i <= 18; i++) for (int i = 1; i <= 19; i++)
{ {
printf("day %d:\n", i); printf("day %d:\n", i);