day 9 pt1

src/bin/09.rs

@@ -4,7 +4,7 @@ use itertools::Itertools;
 
 advent_of_code::solution!(9);
 
-pub fn part_one(input: &str) -> Option<u32> {
+pub fn part_one(input: &str) -> Option<u64> {
     // println!("INPUT:");
     // println!("{}", input);
 
@@ -20,7 +20,7 @@ pub fn part_one(input: &str) -> Option<u32> {
 
     let checksum = get_checksum(compressed_blocks);
 
-    Some(checksum as u32)
+    Some(checksum as u64)
 }
 
 pub fn part_two(_input: &str) -> Option<u32> {
@@ -83,13 +83,9 @@ mod tests {
         let input = "2333133121414131402\n";
         let blocks = create_blocks(input.chars().collect_vec());
 
-        let result_str = blocks.iter().fold("".to_string(), |cur, next| {
-            if *next == None {
-                cur + "."
-            } else {
-                cur + &next.unwrap().to_string()
-            }
-        });
+        let result_str: String = blocks.iter().map(|b| {
+            if Option::is_some(b) { b.unwrap().to_string() } else { ".".to_string() }
+        }).collect();
 
         assert_eq!(result_str, "00...111...2...333.44.5555.6666.777.888899");
     }