day06: Add comment

pedantic79 · Jan 2, 2024 · 0243a3f · 0243a3f
1 parent 2bbcc38
commit 0243a3f
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/src/day06.rs b/src/day06.rs
@@ -47,6 +47,8 @@ pub fn generator_p2(input: &str) -> Vec<usize> {
     process_input(nom_lines(parse_number))(input)
 }
 
+// dist = (x - time) * x
+// 0 = x² - time*x - dist
 fn ways(time: usize, dist: usize) -> usize {
     let pyth = sqrt(time * time - 4 * dist);
     let r0 = (time - pyth) / 2;