wip: solve with range type

src/bin/05.rs

@@ -1,17 +1,32 @@
 use std::{
     cmp::{max, min},
+    ops::Range,
     str::FromStr,
 };
 
 use aoc::parsers::to_vec;
 
-type PairRange = (u64, u64);
+trait RangeExt {
+    fn overlaps(&self, other: &Self) -> bool;
+}
+
+impl<T> RangeExt for Range<T>
+where
+    T: PartialOrd,
+{
+    fn overlaps(&self, other: &Self) -> bool {
+        self.contains(&other.start) || self.contains(&other.end)
+    }
+}
+
+fn build_range(start: u64, range: u64) -> Range<u64> {
+    start..(start + range)
+}
 
 #[derive(Debug)]
 struct Mapping {
-    destination: u64,
+    destination: Range<u64>,
-    source: u64,
+    source: Range<u64>,
-    range: u64,
 }
 
 struct ParseMappingError;
@@ -22,34 +37,26 @@ impl FromStr for Mapping {
         let nums: Vec<u64> = to_vec(s, ' ');
 
         Ok(Self {
-            destination: nums[0],
+            destination: build_range(nums[2], nums[0]),
-            source: nums[1],
+            source: build_range(nums[1], nums[0]),
-            range: nums[2],
         })
     }
 }
 
 impl Mapping {
-    fn contains(&self, n: u64) -> bool {
-        n >= self.source && n < self.source + self.range
-    }
-
-    fn contains_any(&self, (s, r): PairRange) -> bool {
-        s < self.source + self.range && s + r > self.source
-    }
-
     fn map(&self, n: u64) -> u64 {
-        let shift = n - self.source;
+        let shift = n - self.source.start;
-        self.destination + shift
+        self.destination.start + shift
     }
 
-    fn split_range(&self, (s, r): PairRange) -> [Option<PairRange>; 3] {
+    fn split_range(&self, r: Range<u64>) -> [Option<Range<u64>>; 3] {
         let mut fences = [
-            s,
+            r.start,
-            s + r,
+            r.end,
-            max(self.source, s),
+            max(self.source.start, r.start),
-            min(self.source + self.range, s + r),
+            min(self.source.end, r.end),
         ];
+
         fences.sort();
 
         let mut v = Vec::new();
@@ -58,13 +65,13 @@ impl Mapping {
             let f = fences[i];
             let nf = fences[i + 1];
             if f != nf {
-                v.push(Some((f, nf - f)))
+                v.push(Some(f..(nf - f)))
             } else {
                 v.push(None)
             }
         }
 
-        v[..3].try_into().unwrap()
+        [v[0], v[1], v[2]]
     }
 }