more cleanup

- fix all clippy warnings
- add times(n: usize) iterator

Signed-off-by: Stephen Waits <swaits@amazon.com>

src/day08.rs

@@ -132,13 +132,7 @@ impl Console {
             .filter(|i| match self.program[*i as usize] {
                 // filter instructions we can modify
                 Instruction::Jmp(_) => true,
-                Instruction::Nop(n) => {
-                    if n != 0 {
-                        true
-                    } else {
-                        false
-                    }
-                }
+                Instruction::Nop(n) => n != 0,
                 _ => false,
             })
             .collect();
@@ -146,7 +140,7 @@ impl Console {
         // now test each of these candidates by exchanging jmp <=> nop
         for i in candidate_indices {
             // save original instruction
-            let original_instruction = self.program[i].clone();
+            let original_instruction = self.program[i];
 
             // exchange jmp<=>nop
             self.program[i] = match &self.program[i] {

src/day09.rs

@@ -3,7 +3,7 @@
 use crate::utils;
 use anyhow::{anyhow, Result};
 
-fn is_bad(data: &Vec<i64>, n: usize, i: usize) -> Result<i64> {
+fn is_bad(data: &[i64], n: usize, i: usize) -> Result<i64> {
     let prev_n = &data[i - n..i];
     if !utils::combinations(2, prev_n.len()).any(|c| data[i] == prev_n[c[0]] + prev_n[c[1]]) {
         Ok(data[i])
@@ -12,7 +12,7 @@ fn is_bad(data: &Vec<i64>, n: usize, i: usize) -> Result<i64> {
     }
 }
 
-fn find_first_bad(data: &Vec<i64>, n: usize, start: usize) -> Result<i64> {
+fn find_first_bad(data: &[i64], n: usize, start: usize) -> Result<i64> {
     for i in start..data.len() {
         let ret = is_bad(data, n, i);
         if ret.is_ok() {
@@ -22,7 +22,7 @@ fn find_first_bad(data: &Vec<i64>, n: usize, start: usize) -> Result<i64> {
     Err(anyhow!("no result found"))
 }
 
-fn find_contiguous_set(data: &Vec<i64>, x: i64) -> Result<i64> {
+fn find_contiguous_set(data: &[i64], x: i64) -> Result<i64> {
     for set_size in 2..data.len() - 1 {
         for i in 0..data.len() - set_size {
             if data[i..i + set_size].iter().sum::<i64>() == x {

src/day10.rs

@@ -3,7 +3,7 @@
 use crate::utils;
 use anyhow::Result;
 
-pub fn count_diff1_diff3(diffs: &Vec<i64>) -> usize {
+pub fn count_diff1_diff3(diffs: &[i64]) -> usize {
     let diff_1 = diffs.iter().filter(|n| **n == 1).count();
     let diff_3 = diffs.iter().filter(|n| **n == 3).count();
     diff_1 * diff_3
@@ -21,7 +21,7 @@ fn paths_by_runlength(runlength: usize) -> usize {
     p[runlength % L]
 }
 
-fn count_paths(diffs: &Vec<i64>) -> usize {
+fn count_paths(diffs: &[i64]) -> usize {
     // count the runs of 1s
     let mut last_diff: i64 = 0;
     let mut runlength: usize = 1;
@@ -59,7 +59,7 @@ pub fn run() -> Result<(usize, usize)> {
         .iter()
         .enumerate()
         .take(data.len() - 1)
-        .map(|(i, _)| (&data[i] - &data[i + 1]).abs())
+        .map(|(i, _)| (data[i] - data[i + 1]).abs())
         .collect();
 
     let p1 = count_diff1_diff3(&diffs);

src/day11.rs

@@ -12,7 +12,7 @@ enum Location {
 
 // compute the 8 immediately adjacent coordinates which contian chairs
 fn adjacent_coords(
-    map: &Vec<Vec<Location>>,
+    map: &[Vec<Location>],
     pos: (usize, usize),
     max: (usize, usize),
 ) -> Vec<(usize, usize)> {
@@ -34,7 +34,7 @@ fn adjacent_coords(
 }
 
 // precompute all the immediately adjacent chairs for all positions on a map
-fn compute_basic_adjacency(map: &Vec<Vec<Location>>) -> Vec<Vec<Vec<(usize, usize)>>> {
+fn compute_basic_adjacency(map: &[Vec<Location>]) -> Vec<Vec<Vec<(usize, usize)>>> {
     (0..map.len())
         .map(|row| {
             (0..map[row].len())
@@ -47,7 +47,7 @@ fn compute_basic_adjacency(map: &Vec<Vec<Location>>) -> Vec<Vec<Vec<(usize, usiz
 // search in one direction from a position until finding a chair (used to compute
 // advanced adjacency
 fn search_direction_for_chair(
-    map: &Vec<Vec<Location>>,
+    map: &[Vec<Location>],
     start: (usize, usize),
     step: &(i32, i32),
 ) -> Option<(usize, usize)> {
@@ -65,7 +65,7 @@ fn search_direction_for_chair(
 }
 
 // precompute all the directionally adjacent chairs for all positions on a map
-fn compute_advanced_adjacency(map: &Vec<Vec<Location>>) -> Vec<Vec<Vec<(usize, usize)>>> {
+fn compute_advanced_adjacency(map: &[Vec<Location>]) -> Vec<Vec<Vec<(usize, usize)>>> {
     // figure out our eight direction step values
     let dirs: Vec<(i32, i32)> = (-1..2)
         .flat_map(|i| (-1..2).map(move |j| (i, j)))
@@ -79,7 +79,7 @@ fn compute_advanced_adjacency(map: &Vec<Vec<Location>>) -> Vec<Vec<Vec<(usize, u
                 .map(|j| {
                     dirs.iter()
                         .filter_map(move |d| {
-                            let dir = d.clone();
+                            let dir = *d;
                             search_direction_for_chair(map, (i, j), &dir)
                         })
                         .collect()
@@ -92,7 +92,7 @@ fn compute_advanced_adjacency(map: &Vec<Vec<Location>>) -> Vec<Vec<Vec<(usize, u
 // run the seating algorithm, return the total number of changes
 fn seating_round(
     map: &mut Vec<Vec<Location>>,
-    adj: &Vec<Vec<Vec<(usize, usize)>>>,
+    adj: &[Vec<Vec<(usize, usize)>>],
     occupied_threshold: usize,
 ) -> usize {
     let mut changes: Vec<(usize, usize, Location)> = Vec::new();
@@ -123,21 +123,15 @@ fn seating_round(
         }
     }
 
-    changes.iter().for_each(|c| map[c.0][c.1] = c.2.clone());
+    changes.iter().for_each(|c| map[c.0][c.1] = c.2);
     changes.len()
 }
 
 // coutnt occupised seats on a given map
-fn count_occupied(map: &Vec<Vec<Location>>) -> usize {
-    let mut count = 0;
-    for i in 0..map.len() {
-        for j in 0..map[i].len() {
-            if map[i][j] == Location::Occupied {
-                count += 1
-            }
-        }
-    }
-    count
+fn count_occupied(map: &[Vec<Location>]) -> usize {
+    map.iter()
+        .flat_map(|row| row.iter().filter(|cell| **cell == Location::Occupied))
+        .count()
 }
 
 // main
@@ -167,7 +161,7 @@ pub fn run() -> Result<(usize, usize)> {
     drop(map1);
 
     // run seating alogirthm using advanced adjacency and occupied threshold of 5
-    let mut map2 = starting_map.clone();
+    let mut map2 = starting_map;
     let advanced_adjacency = compute_advanced_adjacency(&map2);
     while seating_round(&mut map2, &advanced_adjacency, 5) > 0 {}
     let p2 = count_occupied(&map2);

src/day12.rs

@@ -16,8 +16,6 @@ fn navigate(data: &str) -> usize {
             "S" => pos_n -= dist,
             "E" => pos_e += dist,
             "W" => pos_e -= dist,
-            "L" => heading = (heading + 360 - dist) % 360,
-            "R" => heading = (heading + dist) % 360,
             "F" => match heading {
                 0 => pos_n += dist,
                 90 => pos_e += dist,
@@ -26,6 +24,8 @@ fn navigate(data: &str) -> usize {
                 360 => pos_n += dist,
                 _ => panic!("non cardinal heading!"),
             },
+            "L" => heading = (heading + 360 - dist) % 360,
+            "R" => heading = (heading + dist) % 360,
             _ => panic!("bad direction!"),
         }
     });
@@ -40,12 +40,15 @@ fn navigate2(data: &str) -> usize {
         let dir = &l[0..1];
         let dist = &l[1..].parse::<i64>().expect("int parse error");
 
-        match dir {
-            "N" => wpt_n += dist,
-            "S" => wpt_n -= dist,
-            "E" => wpt_e += dist,
-            "W" => wpt_e -= dist,
-            "L" | "R" => match (dir, dist) {
+        match (dir, dist) {
+            ("N", _) => wpt_n += dist,
+            ("S", _) => wpt_n -= dist,
+            ("E", _) => wpt_e += dist,
+            ("W", _) => wpt_e -= dist,
+            ("F", _) => {
+                ship_n += dist * wpt_n;
+                ship_e += dist * wpt_e;
+            }
             ("L", 90) | ("R", 270) => {
                 wpt_n = -wpt_n;
                 mem::swap(&mut wpt_n, &mut wpt_e);
@@ -54,17 +57,11 @@ fn navigate2(data: &str) -> usize {
                 wpt_e = -wpt_e;
                 mem::swap(&mut wpt_n, &mut wpt_e);
             }
-                (_, 180) => {
+            ("L", 180) | ("R", 180) => {
                 wpt_n = -wpt_n;
                 wpt_e = -wpt_e;
             }
             _ => panic!("bad direction!"),
-            },
-            "F" => {
-                ship_n += dist * wpt_n;
-                ship_e += dist * wpt_e;
-            }
-            _ => panic!("bad direction!"),
         }
     });
 

src/utils.rs

@@ -1,7 +1,7 @@
 // ==== utilities
 
 use anyhow::Result;
-use std::fs;
+use std::{fs, iter};
 
 pub fn read_i64s(filename: &str) -> Result<Vec<i64>> {
     Ok(read_file(filename)?
@@ -23,6 +23,11 @@ pub fn parse_usize_in_range(s: &str, min: usize, max: usize) -> Option<usize> {
     }
 }
 
+#[allow(dead_code)]
+pub fn times(n: usize) -> impl Iterator<Item = usize> {
+    iter::repeat(()).take(n).enumerate().map(|(i, _)| i)
+}
+
 // Lexicographic combinations.
 //
 // This algorithm generates all t-combinations of n numbers {0, 1, ..., n-1},