prefisinished 7 just storing

day7/Cargo.lock

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+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "day7"
+version = "0.1.0"

day7/Cargo.toml

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+[package]
+name = "day7"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

day7/src/main.rs

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+use std::fs::File;
+use std::io::{prelude::*, BufReader};
+
+struct MyFile {
+    name: String,
+    size: usize,
+}
+
+struct MyDir <'a>{
+    name: String,
+    objects: Vec<FileSytemTypes<'a>>,
+    //TODO should this bee reference counted
+    parent_dir: Option<&'a MyDir<'a>>,
+}
+
+impl <'a> MyDir<'a> {
+    fn new(name: impl Into<String>, parent_dir: Option<&'a MyDir<'a>>) -> Self {
+        let name: String = name.into();
+        let parent_dir = match parent_dir {
+            Some(x) => Some(x),
+            None => None,
+        };
+        MyDir {
+            name,
+            objects: Vec::new(),
+            parent_dir,
+        }
+    }
+}
+
+enum FileSytemTypes <'a>{
+    MyFile(MyFile),
+    MyDir(&'a Box<MyDir<'a>>),
+}
+
+fn main() -> std::io::Result<()> {
+    //Read in file
+    let file = File::open("input")?;
+    let reader = BufReader::new(file);
+
+    //create root file object on heap
+    let root = Box::new(MyDir::new("/", None));
+    let mut ls_mode = false;
+    //set a pointer to the currently on MyDir, in this case start at roo
+    let mut cursor = root.as_mut();
+
+    // loop through the input files lines
+    reader.lines().for_each(|line| {
+        //need to unwrap the line cause lines() returns an Option
+        let line = line.unwrap();
+        //if we are listing files we need to  get the information from the input
+        if ls_mode && line.as_bytes()[0] != '$' as u8 {
+            //do adding to cursor
+            match line.split_whitespace().collect::<Vec<_>>()[..] {
+                ["dir", name] => { // sub directories start with dir
+                    // create the subdirectory on the heap
+                    let new_directory = &Box::new(MyDir::new(name, Some(cursor)));
+                    // attach the new directory to the current directory
+                    let obj: &mut Vec<FileSytemTypes<'_>> = cursor.objects.as_mut();
+                    obj.push(FileSytemTypes::MyDir(new_directory));
+                }
+                [size, name] => cursor.objects.push(FileSytemTypes::MyFile(MyFile {
+                    name: name.to_string(),
+                    size: size.parse::<usize>().unwrap(),
+                })),
+                _ => panic!("oops {}", line),
+            };
+            // end the for_each
+            return;
+        }
+        ls_mode = false;
+        //parse all other lines as commands
+        match line.split_whitespace().collect::<Vec<_>>()[..] {
+            ["$", "ls"] => ls_mode = true,
+            ["$", "cd", "/"] => cursor = root.as_mut(), //set current directory back to root
+            ["$", "cd", ".."] => {
+                // set current directory to the parent directory
+                cursor = match cursor.parent_dir {
+                    Some( x) => &mut x,
+                    _ => panic!("issue {}", line),
+                }
+            }
+            ["$", "cd", dir] => {
+                //set the currect directory to the subdirectory named dir
+                cursor = cursor
+                    .objects
+                    .iter()
+                    .filter_map(|x| match x {
+                        FileSytemTypes::MyDir(y) => Some(y.as_mut()),
+                        _ => None,
+                    })
+                    .find(|x| x.name == dir)
+                    .unwrap();
+            }
+            _ => panic!("unknown command {}", line),
+        }
+    });
+
+    Ok(())
+}