Advent 2023 Day 11

advent_of_code_2023/day11/main1.rs

@@ -0,0 +1,73 @@
+use std::fs::read_to_string;
+
+fn difference(lhs: usize, rhs: usize) -> usize {
+    if lhs > rhs {
+        return lhs - rhs;
+    }
+    rhs - lhs
+}
+
+fn main() {
+    let input = read_to_string("input.txt").unwrap();
+    let mut starmap = input.lines().map(|line| {
+        let mut vec: Vec<u8> = Vec::new();
+        vec.extend_from_slice(line.as_bytes());
+        vec
+    }).collect::<Vec<_>>();
+
+    let mut index = 0;
+    loop {
+        if index == starmap.len() {
+            break;
+        }
+
+        if starmap[index].iter().filter(|ch| { **ch == b'#' }).count() == 0 {
+            starmap.insert(index, starmap[index].clone());
+            index += 1;
+        }
+
+        index += 1;
+    }
+
+    index = 0;
+    loop {
+        if index >= starmap[0].len() {
+            break;
+        }
+
+        let mut sum = 0;
+        for line in &starmap {
+            if line[index] == b'#' {
+                sum += 1;
+            }
+        }
+
+        if sum == 0 {
+            for line in &mut starmap {    
+                line.insert(index, b'.');
+            }
+            index += 1;
+        }
+
+        index += 1;
+    }
+
+    let mut stars: Vec<(usize, usize)> = Vec::new();
+    for row in 0..starmap.len() {
+        for col in 0..starmap[row].len() {
+            if starmap[row][col] == b'#' {
+                stars.push((row, col));
+            }
+        }
+    }
+
+    let mut sum_difference = 0;
+    for start_idx in 0..stars.len() {
+        for inner_idx in start_idx..stars.len() {
+            sum_difference += difference(stars[start_idx].0, stars[inner_idx].0);
+            sum_difference += difference(stars[start_idx].1, stars[inner_idx].1);
+        }
+    }
+
+    println!("Sum of ranges: {}", sum_difference);
+}