ineffective noodling

src/main.rs

@@ -1,7 +1,9 @@
 use std::{
-    collections::HashMap,
+    cmp,
+    collections::{HashMap, hash_map::Entry},
     env,
     io::{self, BufRead, BufReader},
+    process,
 };
 
 use crate::letterset::LetterSet;
@@ -9,7 +11,7 @@ use crate::letterset::LetterSet;
 mod letterset;
 
 fn main() {
-    let dictionary: Vec<_> = BufReader::new(io::stdin().lock())
+    let mut dictionary: Vec<_> = BufReader::new(io::stdin().lock())
         .lines()
         .map(|line| {
             let word = line.unwrap();
@@ -18,24 +20,46 @@ fn main() {
         })
         .collect();
 
-    println!(
+    let target = env::args().nth(1).map_or(LetterSet::FULL, LetterSet::from);
-        "{:#?}",
+    println!("letter count: {}", target.len());
-        solve(
+    let Some((len, path)) = solve(&mut dictionary, target) else {
-            &dictionary,
+        println!("failed :(");
-            env::args().nth(1).map_or(LetterSet::FULL, LetterSet::from)
+        process::exit(1);
-        )
+    };
-    );
+    println!("{len}: {}", path.join(" "));
 }
 
-fn solve(dictionary: &[(String, LetterSet)], target: LetterSet) -> Option<(u16, Vec<String>)> {
+fn solve(dictionary: &mut [(String, LetterSet)], target: LetterSet) -> Option<(u16, Vec<String>)> {
     let mut bests = HashMap::new();
     bests.insert(LetterSet::EMPTY, (0, Vec::new()));
 
+    // WORDS WITH DUPES MUST BE AT THE END!
+    dictionary.sort_by_key(|(word, ls)| {
+        let dupes = word.len() - usize::from(ls.len());
+        (dupes, cmp::Reverse(ls.len()))
+    });
+
+    for (word, ls) in dictionary.iter() {
+        let len = u16::try_from(word.len()).unwrap();
+        match bests.entry(*ls) {
+            Entry::Occupied(mut occupied) => {
+                if occupied.get().0 > len {
+                    occupied.insert((len, vec![word.clone()]));
+                }
+            }
+            Entry::Vacant(vacant) => {
+                vacant.insert((len, vec![word.clone()]));
+            }
+        }
+    }
+
     score(dictionary, &mut bests, target);
 
     bests.get(&target).cloned()
 }
 
+// TODO: perhaps bottom up? (pick or no pick) (real potential!)
+// the problem is that i'm not *improving* scores, i use the best one immediately
 // length doesn't include spaces. i think that's okay
 // assumes that `bests[LetterSet::EMPTY] == (0, Vec::new())`
 fn score(
@@ -49,16 +73,17 @@ fn score(
 
     let Some((word, ls, score)) = dictionary
         .iter()
-        .filter(|(_, ls)| !remaining.intersection(*ls).is_empty())
+        .filter(|(_, ls)| {
+            ls.intersection(remaining.negation()).is_empty()
+                || !remaining.intersection(*ls).is_empty()
+            //&& ls.intersection(remaining.negation()).len() <= 1
+        })
         .map(|(word, ls)| {
+            let rest_score = score(dictionary, bests, remaining.difference(*ls));
             (
                 word,
                 ls,
-                (u16::try_from(word.len()).unwrap()).saturating_add(score(
+                (u16::try_from(word.len()).unwrap()).saturating_add(rest_score),
-                    dictionary,
-                    bests,
-                    remaining.difference(*ls),
-                )),
             )
         })
         .min_by_key(|(_, _, score)| *score)