Account for remainder in 2015 Day 21

Author: erghelium

src/year2015/day21.rs

@@ -74,8 +74,18 @@ pub fn parse(input: &str) -> Vec<Result> {
             for &third in &combinations {
                 let Item { cost, damage, armor } = first + second + third;
 
-                let hero_turns = boss_health / (damage - boss_armor).max(1);
-                let boss_turns = 100 / (boss_damage - armor).max(1);
+                let hero_hit = (damage - boss_armor).max(1);
+                let hero_turns = if boss_health % hero_hit == 0 {
+                    boss_health / hero_hit
+                } else {
+                    boss_health / hero_hit + 1
+                };
+                let boss_hit = (boss_damage - armor).max(1);
+                let boss_turns = if 100 % boss_hit == 0 {
+                    100 / boss_hit
+                } else {
+                    100 / boss_hit + 1
+                };
                 let win = hero_turns <= boss_turns;
 
                 results.push((win, cost));