Implement 2025 - Day 6 - Part 2

2025/06.rs

@@ -10,32 +10,50 @@ enum Operation {
 }
 
 fn main() {
-    let raw_grid: Vec<_> = CONTENT.lines().map(|l| l.trim()).filter(|l| !l.is_empty()).map(|l| {
-        l.split(' ').map(|c| c.trim()).filter(|c| !c.is_empty()).collect::<Vec<_>>()
+    let raw_grid: Vec<_> = CONTENT.lines().map(|l| {
+        l.chars().collect::<Vec<_>>()
     }).collect();
-
     println!("Raw-Grid\n{:?}", raw_grid);
 
+    let height = raw_grid.len();
+    let width = raw_grid[0].len();
+
+    let separators: Vec<_> = (0..width).filter(|pidx| {
+        raw_grid.iter().map(|row| row[*pidx]).all(|c| c == ' ')
+    }).collect();
+    println!("Separators {:?}", separators);
+
+    let ranges: Vec<_> = (core::iter::once(0).chain(separators.iter().copied().map(|v| v+1))).zip(separators.iter().copied().chain(core::iter::once(width))).map(|(s, e)| s..e).collect();
+    println!("Ranges {:?}", ranges);
+
     let mut result = 0;
 
-    let problem_count = raw_grid[0].len();
-    for p_idx in 0..problem_count {
-        let op = match raw_grid.last().map(|r| r[p_idx]) {
-            Some("+") => Operation::Add,
-            Some("*") => Operation::Mul,
-            other => unreachable!("Unexpected Operation {:?}", other),
-        };
+    for r in ranges.iter().cloned() {
+        println!("Range {:?}", r);
 
-        let elem_iter = raw_grid.iter().take(raw_grid.len()-1).map(|r| r[p_idx]).map(|v| v.parse::<usize>().unwrap());
-
-        let value = match op {
-            Operation::Add => elem_iter.sum::<usize>(),
-            Operation::Mul => elem_iter.product::<usize>()
-        };
-        println!("V {}", value);
-
-        result += value;
+        let values: Vec<_> = r.clone().rev().map(|p| {
+            raw_grid.iter().enumerate().take(height-1).map(|(i, r)| (i, r[p])).fold(0usize, |acc, (i, v)| {
+                if v == ' ' {
+                    return acc;
                 }
 
-    println!("Result {}", result);
+                acc * 10usize + v.to_digit(10).unwrap() as usize
+            })
+        }).collect();
+        println!("Values: {:?}", values);
+
+        let operation = raw_grid[height-1][r].iter().find(|c| **c != ' ').unwrap();
+        println!("Operation {:?}", operation);
+
+        let calc_res = match operation {
+            '+' => values.into_iter().sum::<usize>(),
+            '*' => values.into_iter().product::<usize>(),
+            other => unreachable!("Unexpected Operation {:?}", other),
+        };
+        println!("Calculation {:?}", calc_res);
+
+        result += calc_res;
+    }
+
+    println!("result {:?}", result);
 }