Rewrote code for part 2

december_6/src/main.rs

@@ -1,40 +1,48 @@
 use std::{fs::read_to_string};
 
 const ITERATIONS: u32 = 256;
-const NEW_FISH_LIFETIME: u8 = 8;
 
 fn main() {
     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 fish: Vec<u8> =  split_input.iter().map(
+    let starting_fishes: Vec<u8> = split_input.iter().map(
         |x| x.parse::<u8>().unwrap()
     ).collect();
 
-    print_fish(&fish, -1);
+    let mut fish: Vec<u64> = vec![0,0,0,0,0,0,0,0,0];
 
-    for _i in 1..ITERATIONS + 1 {
-        for fi in 0..fish.len() {
-            let current_timer = fish[fi];
-            if current_timer == 0 {
-                fish[fi] = 6;
-                fish.push(NEW_FISH_LIFETIME);
-            } else {
-                fish[fi] = current_timer - 1;
-            }
-        }
-        println!("Interation {} of {}, {}", _i, ITERATIONS, fish.len());
-        //print_fish(&fish, _i as i32);
+    for fi in starting_fishes{
+        fish[fi as usize] = fish[fi as usize] + 1;
     }
 
+     print_fish(&fish, -1);
 
-    println!("Final Number of Fish: {}", fish.len());
+    for _i in 1..ITERATIONS + 1 {
+        let zero_fish = fish[0];
+
+        for timer in 1..=8 {
+            fish[timer-1] = fish[timer];
+        }
+
+        fish[6] = fish[6] + zero_fish;
+        fish[8] = zero_fish;
+        print_fish(&fish, _i as i32);
+    }
+
+    let mut sum: u128 = 0;
+    for f in fish {
+        sum += f as u128;
+    }
+    println!("Final Number of Fish: {}", sum);
 }
 
-fn print_fish(fish: &Vec<u8>, iteration: i32){
+
+
+fn print_fish(fish: &Vec<u64>, iteration: i32){
     let fish_copy = fish.to_owned();
     print!("Iteration: {}, Fish: ", iteration);
-    for f in fish_copy {
-        print!("{}, ", f);
+    for f in 0..fish_copy.len() {
+        print!("{},{}  ", f, fish_copy[f]);
     }
     print!("\n");
 }