Advent of Code 2022 day 7

advent_of_code_2022/day7/main.cc

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+#include <charconv>
+#include <fmt/format.h>
+#include <iostream>
+#include <map>
+
+struct Entry
+{
+    int size{}; // -1 = dir
+    std::map<std::string, std::shared_ptr<Entry>> entries;
+};
+using EntryPtr = std::shared_ptr<Entry>;
+
+std::uint64_t calculate(std::uint64_t& score, const EntryPtr& entry)
+{
+    if (entry->size != -1)
+        return entry->size;
+    
+    std::uint64_t size{};
+    for (const auto& [name, ptr] : entry->entries)
+    {
+        if (name == "..")
+            continue;
+        size += calculate(score, ptr);
+    }
+
+    if (size <= 100'000)
+        score += size;
+    return size;
+}
+
+std::uint64_t find(std::uint64_t& score, const EntryPtr& entry, std::uint64_t free_required)
+{
+    if (entry->size != -1)
+        return entry->size;
+
+    std::uint64_t size{};
+    for (const auto& [name, ptr] : entry->entries)
+    {
+        if (name == "..")
+            continue;
+        size += find(score, ptr, free_required);
+    }
+
+    if (size >= free_required)
+        score = std::min(score, size);
+
+    return size;
+}
+
+void print_folder(const std::string& name, const EntryPtr& folder, int level = 0)
+{
+    if (name == "..")
+        return;
+    fmt::print("{:{}}-", ' ', level);
+    if (folder->size == -1)
+    {
+        fmt::print("{}\n", name);
+        for (const auto& [folder_name, entry] : folder->entries)
+            print_folder(folder_name, entry, level + 4);
+    }
+    else
+        fmt::print("{} (size: {})\n", name, folder->size);
+}
+
+int main()
+{
+    std::string buffer;
+    EntryPtr root = std::make_shared<Entry>();
+    root->size = -1;
+    EntryPtr current;
+
+    while (true)
+    {
+        std::getline(std::cin, buffer);
+        if (buffer.find("$ c") == 0)
+        {
+            auto folder = buffer.substr(5);
+            
+            if (folder == "/")
+                current = root;
+            else
+                current = current->entries[folder];
+        }
+        else if (buffer.find("$ l") == 0)
+        { } // nothing?
+        else if (buffer[0] == 'd') // dir
+        {
+            auto name = buffer.substr(4);
+            auto entry = std::make_shared<Entry>();
+            entry->size = -1;
+            entry->entries[".."] = current;
+            current->entries[name] = entry;
+        }
+        else
+        {
+            auto entry = std::make_shared<Entry>();
+            std::from_chars(buffer.data(), buffer.data() + buffer.size(), entry->size);
+            current->entries[buffer.substr(buffer.find(' ') + 1)] = entry;
+        }
+
+        if (std::cin.eof())
+            break;
+    }
+
+    // print_folder("/", root);
+
+    std::uint64_t score{};
+    std::uint64_t to_free = 70'000'000;
+
+    std::uint64_t total_size = calculate(score, root);
+    find(to_free, root, 30'000'000 - (70'000'000 - total_size));
+
+    fmt::print("Result part 1: {}\n", score);
+    fmt::print("Result part 2: {}\n", to_free);
+}

advent_of_code_2022/day7/test.txt

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+$ cd /
+$ ls
+dir a
+14848514 b.txt
+8504156 c.dat
+dir d
+$ cd a
+$ ls
+dir e
+29116 f
+2557 g
+62596 h.lst
+$ cd e
+$ ls
+584 i
+$ cd ..
+$ cd ..
+$ cd d
+$ ls
+4060174 j
+8033020 d.log
+5626152 d.ext
+7214296 k