Finished December 7

december_7/src/main.rs

@@ -1,3 +1,33 @@
+use std::{fs::read_to_string};
+
 fn main() {
-    println!("Hello, world!");
+    let input_char_vec = read_to_string("./input.txt").expect("ERROR reading file");
+    let split_input = input_char_vec.split(",").collect::<Vec<&str>>();
+
+    let mut min_fuel = u32::MAX;
+    let mut cheapest_position: u32 = 0;
+
+    let crab_positions: Vec<u32> = split_input.iter().map(
+        |x| x.parse::<u32>().unwrap()
+    ).collect();
+    let max_depth = crab_positions.iter().max().unwrap().to_owned();
+
+
+    for test_target_depth in 0..=max_depth {
+        let mut needed_fuel_for_depth = 0;
+        for crab in crab_positions.iter() {
+            let distance = (test_target_depth as i32 - crab.to_owned() as i32).abs() as u32;
+            let mut needed_fuel = 0;
+            for d in 0..=distance {
+                needed_fuel += d;
+            }
+            needed_fuel_for_depth += needed_fuel;
+        }
+        if needed_fuel_for_depth < min_fuel {
+            min_fuel = needed_fuel_for_depth;
+            cheapest_position = test_target_depth;
+        }
+    }
+
+    println!("Cheapest Postion is {} with a fuel usage of {}", cheapest_position, min_fuel);
 }