wathiede/advent
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Address some TODOs.

Browse Source
This commit is contained in:
Bill Thiede 2020-12-09 17:56:42 -08:00
parent 5dc51a050f
commit 68d161f2f7
1 changed files with 7 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
2020/src/day9.rs
View File

@ -100,9 +100,7 @@ fn solution1_impl(nums: &[usize], win_size: usize) -> usize {
false false
}) })
// TODO(wathiede): try find_map() .find_map(|chunk| Some(chunk[win_size]))
.map(|chunk| chunk[win_size])
.nth(0)
.unwrap() .unwrap()
} }
@ -112,8 +110,12 @@ fn solution1(nums: &[usize]) -> usize {
} }
fn sum_min_max(low: usize, hi: usize, nums: &[usize]) -> usize { fn sum_min_max(low: usize, hi: usize, nums: &[usize]) -> usize {
// TODO(wathiede): rewrite with fold to do it in one pass. let (min, max) = nums[low..hi]
nums[low..hi].iter().min().unwrap() + nums[low..hi].iter().max().unwrap() .iter()
.fold((usize::MAX, 0), |(min, max), &n| {
(std::cmp::min(min, n), std::cmp::max(max, n))
});
min + max
} }
// If contiguous numbers adding up to `sum` are found, the hi index (inclusive) is returned. // If contiguous numbers adding up to `sum` are found, the hi index (inclusive) is returned.
@ -134,7 +136,6 @@ fn find_sum_at(low: usize, nums: &[usize], sum: usize) -> Option<usize> {
fn solution2_impl(nums: &[usize], win_size: usize) -> usize { fn solution2_impl(nums: &[usize], win_size: usize) -> usize {
let sum = solution1_impl(nums, win_size); let sum = solution1_impl(nums, win_size);
dbg!(sum);
for low in 0..nums.len() - 1 { for low in 0..nums.len() - 1 {
if let Some(hi) = find_sum_at(low, nums, sum) { if let Some(hi) = find_sum_at(low, nums, sum) {
return sum_min_max(low, hi, nums); return sum_min_max(low, hi, nums);