[TASK] Solved Day 7

.vscode/launch.json

@@ -0,0 +1,45 @@
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "type": "lldb",
+            "request": "launch",
+            "name": "Debug executable 'advent-of-code-2022-rust'",
+            "cargo": {
+                "args": [
+                    "build",
+                    "--bin=advent-of-code-2022-rust",
+                    "--package=advent-of-code-2022-rust"
+                ],
+                "filter": {
+                    "name": "advent-of-code-2022-rust",
+                    "kind": "bin"
+                }
+            },
+            "args": [],
+            "cwd": "${workspaceFolder}"
+        },
+        {
+            "type": "lldb",
+            "request": "launch",
+            "name": "Debug unit tests in executable 'advent-of-code-2022-rust'",
+            "cargo": {
+                "args": [
+                    "test",
+                    "--no-run",
+                    "--bin=advent-of-code-2022-rust",
+                    "--package=advent-of-code-2022-rust"
+                ],
+                "filter": {
+                    "name": "advent-of-code-2022-rust",
+                    "kind": "bin"
+                }
+            },
+            "args": [],
+            "cwd": "${workspaceFolder}"
+        }
+    ]
+}

src/day7.rs

@@ -1,3 +1,4 @@
+
 use crate::day_solver::DaySolver;
 
 use super::util;
@@ -26,15 +27,15 @@ pub struct Day7 {
 impl Day7 {
 
     pub fn create() -> Self {
-        let lines = util::read_file("input/day7_example.txt");
-        // let lines = util::read_file("input/day7.txt");
+        // let lines = util::read_file("input/day7_example.txt");
+        let lines = util::read_file("input/day7.txt");
 
         let mut lines_iter = lines.iter().peekable();
         let mut commands = Vec::new();
         while let Some(line) = lines_iter.next() {
-            if  line == "$ ls" {
+            if line == "$ ls" {
                 let mut result = Vec::new();
-                if let Some(result_line) = lines_iter.peek() {
+                while let Some(result_line) = lines_iter.peek() {
                     if !result_line.starts_with("$") {
                         if result_line.starts_with("dir") {
                             result.push(FileSystemEntry::Directory {
@@ -48,6 +49,8 @@ impl Day7 {
                             });
                         }
                         lines_iter.next();
+                    } else {
+                        break;
                     }
                 }
                 commands.push(Command::LS {
@@ -60,22 +63,95 @@ impl Day7 {
             }
         }
 
-        println!("{:?}", commands);
+        // println!("{:?}", commands);
         // Put the input into the day struct
         return Day7 {
             commands
         }
     }
+
+    fn calculate_dir_sizes(&self) -> Vec<(Vec<String>, usize)> {
+        let mut dir_stack = Vec::new();
+        let mut size_stack: Vec<usize> = Vec::new();
+        size_stack.push(0);
+        let mut dir_sizes: Vec<(Vec<String>, usize)> = Vec::new();
+        for command in &self.commands {
+    
+            // In the first pass, we only count files directly under it, then in the final pass we also include children.
+            match command {
+                Command::CD { target } => {
+                    if target == ".." {
+                        move_up_dir(&mut dir_sizes, &mut dir_stack, &mut size_stack);
+                    } else if target == "/" {
+                        move_to_root(&mut dir_stack, &mut dir_sizes, &mut size_stack)
+                    } else {
+                        dir_stack.push(target.clone());
+                        size_stack.push(0);
+                    }
+                }
+                Command::LS { result } => {
+                    let file_size: usize = result.iter()
+                        .map(|f| if let FileSystemEntry::File { name: _, size } = f { size.to_owned() } else { 0usize })
+                        .sum();
+                    increment_last(&mut size_stack, file_size);
+                }
+            }
+        }
+        move_to_root(&mut dir_stack, &mut dir_sizes, &mut size_stack);
+        let root_size: usize = size_stack.last().unwrap().to_owned();
+        //  dir_sizes.iter()
+        //     .filter_map(|(dir, size)| if dir.len() == 1 { Some(size) } else { None })
+        //     .sum::<usize>();
+        dir_sizes.push((Vec::new(), root_size));
+        println!("{:?}", dir_sizes.iter().map(|d| format!("/{}: {}", d.0.join("/"), d.1)).collect::<Vec<String>>());
+        dir_sizes
+    }
 }
 
 impl DaySolver for Day7 {
 
 
     fn solve_part1(&mut self) -> String {
-        return 0.to_string();
+
+        let dir_sizes = self.calculate_dir_sizes();
+
+        return dir_sizes.iter()
+            .filter_map(|(_, size)| if size <= &100000usize { Some(size)} else { None })
+            .sum::<usize>().to_string();
     }
 
     fn solve_part2(&mut self) -> String {
-        return 0.to_string();
+
+        let dir_sizes = self.calculate_dir_sizes();
+        let root_size = dir_sizes.last().unwrap().1;
+        let min_delete_size = 30_000_000usize - (70_000_000usize - root_size);
+        return dir_sizes.iter().map(|d| d.1)
+            .filter(|s| s > &min_delete_size)
+            .min().unwrap().to_string();
+    }
+}
+
+fn move_to_root(dir_stack: &mut Vec<String>, dir_sizes: &mut Vec<(Vec<String>, usize)>, size_stack: &mut Vec<usize>) {
+    while !dir_stack.is_empty() {
+        move_up_dir(dir_sizes, dir_stack, size_stack);
+    }
+}
+
+
+fn move_up_dir(dir_sizes: &mut Vec<(Vec<String>, usize)>, dir_stack: &mut Vec<String>, size_stack: &mut Vec<usize>) {
+    // If we leave the directory, we should have collected all sizes of subdirs
+    dir_sizes.push((dir_stack.to_owned(), size_stack.last().unwrap().to_owned()));
+    dir_stack.pop();
+    // We also need to add the child size to the size of the "parent"
+    if let Some(child_size) = size_stack.pop() {
+        increment_last(size_stack, child_size); 
+    } else {
+        println!("I kind of expected to always have a child size?? @ {:?}", dir_stack);
+    }
+}
+
+fn increment_last(size_stack: &mut Vec<usize>, size: usize) {
+    if let Some(last) = size_stack.last_mut() {
+        *last += size;
     }
 }

src/main.rs

@@ -112,7 +112,7 @@ fn solve(day: u8, silent: bool) -> AocBenchResult {
             let (part2, pt2_time) = bench(|| s.solve_part2());
             part2_time = pt2_time;
             if !silent {
-                println!("Day {} Part 1: {}", day, part2);
+                println!("Day {} Part 2: {}", day, part2);
             }
         },
         None => panic!("This day is not yet implemented")