more progress

2017/src/bin/2017_01a.rs

@@ -10,25 +10,19 @@
 use core::read_data;
 
 fn circular_digit_sum(input: &str) -> u32 {
+    let all_chars: Vec<_> = input.chars().collect();
     let mut running_total = 0;
-    let mut first_char = ' ';
-    let mut last_char = ' ';
     let input_length = input.len();
-    for (index, char) in input.chars().enumerate() {
-        if index == 0 {
-            first_char = char;
-        }
-        if index == input_length - 1 {
-            if char == first_char {
-                let num_val = char.to_digit(10).unwrap();
-                running_total += num_val;
+    let half_way = input_length / 2;
+    println!("TOTAL LENGTH FOR INPUT: {input_length} / {half_way}");
+    for (index, char) in all_chars.clone().into_iter().enumerate() {
+        if index < half_way {
+            if all_chars[index] == all_chars[index + half_way] {
+                let val = all_chars[index].to_string().parse::<u32>().unwrap();
+                running_total += (val * 2);
             }
+            println!("Checking {index} against {}", index + half_way);
         }
-        if char == last_char {
-            let num_val = char.to_digit(10).unwrap();
-            running_total += num_val;
-        }
-        last_char = char;
     }
 
     running_total
@@ -38,11 +32,12 @@ fn circular_digit_sum(input: &str) -> u32 {
 fn main() {
     let binding = read_data("2017_01_data.txt");
     let params = vec![
-        ("1122", 3),
-        ("1111", 4),
-        ("1234", 0),
-        ("91212129", 9),
-        (&*binding, 1031)
+        ("1212", 6),
+        ("1221", 0),
+        ("123425", 4),
+        ("123123", 12),
+        ("12131415", 4),
+        (&*binding, 1080)
     ];
 
     for (param, expected) in params {
@@ -52,4 +47,4 @@ fn main() {
         println!("success!");
     }
 }
-// 1031
+// 1080