Merge pull request #102 from jwodder/no-maxtracker

Remove uses of `maxtracker.rs`

Author: jwodder

2017/06a/src/main.rs

@@ -1,4 +1,3 @@
-use adventutil::maxtracker::FirstMaxKeyTracker;
 use adventutil::pullparser::{ParseError, PullParser, Token};
 use adventutil::Input;
 
@@ -7,11 +6,16 @@ struct Banks(Vec<u32>);
 
 impl Banks {
     fn maxpos(&self) -> usize {
-        let mut tracker = FirstMaxKeyTracker::new();
-        for (i, &val) in self.0.iter().enumerate() {
-            tracker.add(i, val);
-        }
-        tracker.get_key().unwrap()
+        self.0
+            .iter()
+            .copied()
+            .enumerate()
+            // Use rev() so that max_by_key() will return the first max element
+            // in self.0 when there's a tie.
+            .rev()
+            .max_by_key(|&(_, val)| val)
+            .unwrap()
+            .0
     }
 
     fn redistribute(&mut self) {

2017/06b/src/main.rs

@@ -1,4 +1,3 @@
-use adventutil::maxtracker::FirstMaxKeyTracker;
 use adventutil::pullparser::{ParseError, PullParser, Token};
 use adventutil::Input;
 
@@ -7,11 +6,16 @@ struct Banks(Vec<u32>);
 
 impl Banks {
     fn maxpos(&self) -> usize {
-        let mut tracker = FirstMaxKeyTracker::new();
-        for (i, &val) in self.0.iter().enumerate() {
-            tracker.add(i, val);
-        }
-        tracker.get_key().unwrap()
+        self.0
+            .iter()
+            .copied()
+            .enumerate()
+            // Use rev() so that max_by_key() will return the first max element
+            // in self.0 when there's a tie.
+            .rev()
+            .max_by_key(|&(_, val)| val)
+            .unwrap()
+            .0
     }
 
     fn redistribute(&mut self) {

2018/05b/src/main.rs

@@ -1,4 +1,3 @@
-use adventutil::maxtracker::MinTracker;
 use adventutil::Input;
 
 /// A doubly-linked list backed by a borrowed slice, with adjacency of elements
@@ -169,23 +168,24 @@ struct Adjacent {
 
 fn solve(s: &str) -> usize {
     let mut list = DoubleIndexList::new(s.as_bytes());
-    let mut shortest = MinTracker::new();
-    for &c in b"abcdefghijklmnopqrstuvwxyz" {
-        if c > b'a' {
-            list.reset();
-        }
-        let mut cursor = list.cursor();
-        while let Some(&sc) = cursor.current() {
-            if sc.to_ascii_lowercase() == c {
-                cursor.remove_current();
-            } else {
-                cursor.move_next();
+    b"abcdefghijklmnopqrstuvwxyz"
+        .iter()
+        .map(|&c| {
+            if c > b'a' {
+                list.reset();
             }
-        }
-        let length = react(&mut list);
-        shortest.add(length);
-    }
-    shortest.get().unwrap()
+            let mut cursor = list.cursor();
+            while let Some(&sc) = cursor.current() {
+                if sc.to_ascii_lowercase() == c {
+                    cursor.remove_current();
+                } else {
+                    cursor.move_next();
+                }
+            }
+            react(&mut list)
+        })
+        .min()
+        .unwrap()
 }
 
 fn react(chars: &mut DoubleIndexList<'_, u8>) -> usize {