d3p2

day3/src/main.rs

@@ -4,21 +4,17 @@ use std::collections::HashSet;
 
 fn main() {
     let input = fs::read_to_string(&env::args().nth(1).unwrap()).unwrap();
+    let mut lines = input.lines();
+    let mut next_line;
 
     let mut sum: u64 = 0;
-    for line in input.lines() {
-        let mut left_chars: HashSet<char> = HashSet::new();
-
-        for (i, c) in line.char_indices() {
-            if i < line.len()/2 {
-                left_chars.insert(c);
-            } else if left_chars.contains(&c) {
-                if c >= 'a' && c <= 'z' {
-                    sum += (c as u64) - ('a' as u64) + 1;
-                } else {
-                    sum += (c as u64) - ('A' as u64) + 27;
-                }
-                break;
+    while (next_line = lines.next()) == () && !next_line.is_none() {
+        let line1: HashSet<char> = next_line.unwrap().chars().collect();
+        let line2: HashSet<char> = lines.next().unwrap().chars().collect();
+        'chars: for c in lines.next().unwrap().chars() {
+            if line1.contains(&c) && line2.contains(&c) {
+                sum += value_of(c);
+                break 'chars;
             }
         }
     }
@@ -26,3 +22,10 @@ fn main() {
     println!("{:?}", sum);
 }
 
+fn value_of(c: char) -> u64 {
+    if c >= 'a' && c <= 'z' {
+        (c as u64) - ('a' as u64) + 1
+    } else {
+        (c as u64) - ('A' as u64) + 27
+    }
+}

day3/src/main1.rs

@@ -0,0 +1,28 @@
+use std::env;
+use std::fs;
+use std::collections::HashSet;
+
+fn main() {
+    let input = fs::read_to_string(&env::args().nth(1).unwrap()).unwrap();
+
+    let mut sum: u64 = 0;
+    for line in input.lines() {
+        let mut left_chars: HashSet<char> = HashSet::new();
+
+        for (i, c) in line.char_indices() {
+            if i < line.len()/2 {
+                left_chars.insert(c);
+            } else if left_chars.contains(&c) {
+                if c >= 'a' && c <= 'z' {
+                    sum += (c as u64) - ('a' as u64) + 1;
+                } else {
+                    sum += (c as u64) - ('A' as u64) + 27;
+                }
+                break;
+            }
+        }
+    }
+
+    println!("{:?}", sum);
+}
+