day11 part2

src/main.rs

@@ -1,4 +1,4 @@
 fn main() {
-    aoc_2018::tasks::day11::task1();
+    // aoc_2018::tasks::day11::task1();
-    // aoc_2018::tasks::day09::task2();
+    aoc_2018::tasks::day11::task2();
 }

src/tasks/day11.rs

@@ -1,11 +1,12 @@
 pub fn task1() {
+    let square_size = 3;
     let serial = 6392;
-    let result = (1..=297)
+    let result = (1..=300 - square_size)
-        .flat_map(|x: i32| (1..=297).map(move |y: i32| (x, y)))
+        .flat_map(|x: i32| (1..=300 - square_size).map(move |y: i32| (x, y)))
         .map(|(x, y)| {
-            let power: i32 = (x..x + 3)
+            let power: i32 = (x..x + square_size)
                 .map(|x| {
-                    (y..y + 3)
+                    (y..y + square_size)
                         .map(move |y| fuel_level(x, y, serial))
                         .sum::<i32>()
                 })
@@ -16,6 +17,30 @@ pub fn task1() {
     println!("{:?}", result);
 }
 
+pub fn task2() {
+    let serial = 6392;
+    let result = (1..300)
+        .map(|square_size| {
+            let result = (1..=300 - square_size)
+                .flat_map(|x: i32| (1..=300 - square_size).map(move |y: i32| (x, y)))
+                .map(|(x, y)| {
+                    let power: i32 = (x..x + square_size)
+                        .map(|x| {
+                            (y..y + square_size)
+                                .map(move |y| fuel_level(x, y, serial))
+                                .sum::<i32>()
+                        })
+                        .sum();
+                    (x, y, power)
+                })
+                .max_by_key(|(_, _, value)| *value)
+                .unwrap();
+            (result.0, result.1, result.2, square_size)
+        })
+        .max_by_key(|result| result.2);
+    println!("{:?}", result);
+}
+
 fn fuel_level(x: i32, y: i32, serial: i32) -> i32 {
     let rack_id = x + 10;
     let mut power = rack_id * y;