Day Eight

4 files changed, 187 insertions, 0 deletions

diff --git a/2022/nim/day08/src/main.nim b/2022/nim/day08/src/main.nim
new file mode 100644
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+++ b/2022/nim/day08/src/main.nim
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+# Day 8: Treetop Tree House
+import std/[os, strutils, sugar]
+
+let input = paramStr(1).readFile().strip().split("\n")
+
+type Tree = object
+  height: int
+  visible: bool
+  scenic: int
+
+var forest = collect:
+  for line in input:
+    collect:
+      for c in line:
+        Tree(height: parseInt($c), visible: false, scenic: 1)
+
+var sum = 0
+var max = 0
+
+template gaze(s: seq[seq[Tree]], a, b: iterable[int], min: int): int =
+  var result = 0
+  block loop:
+    for k in a:
+      for l in b:
+        inc result
+        if s[k][l].height >= min:
+          break loop
+  result
+
+for i in 0 ..< forest.len:
+  var min = (-1, -1, -1, -1)
+  for j in 0 ..< forest.len:
+    let k = forest[0].len - 1 - j
+
+    if forest[i][j].height > min[0]:
+      min[0] = forest[i][j].height
+      if not forest[i][j].visible: inc sum
+      forest[i][j].visible = true
+
+    if forest[i][k].height > min[1]:
+      min[1] = forest[i][k].height
+      if not forest[i][k].visible: inc sum
+      forest[i][k].visible = true
+
+    if forest[j][i].height > min[2]:
+      min[2] = forest[j][i].height
+      if not forest[j][i].visible: inc sum
+      forest[j][i].visible = true
+
+    if forest[k][i].height > min[3]:
+      min[3] = forest[k][i].height
+      if not forest[k][i].visible: inc sum
+      forest[k][i].visible = true
+
+    let min = forest[i][j].height
+
+    forest[i][j].scenic *= forest.gaze(countdown(i-1, 0), j..j, min)
+    forest[i][j].scenic *= forest.gaze(i..i, countdown(j-1, 0), min)
+    forest[i][j].scenic *= forest.gaze(i+1 ..< forest.len, j..j, min)
+    forest[i][j].scenic *= forest.gaze(i..i, j+1 ..< forest.len, min)
+
+    if forest[i][j].scenic > max:
+      max = forest[i][j].scenic
+
+echo sum
+echo max
diff --git a/2022/rust/day08/Cargo.lock b/2022/rust/day08/Cargo.lock
new file mode 100644
index 0000000..66a960e
--- /dev/null
+++ b/2022/rust/day08/Cargo.lock
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+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "day08"
+version = "0.1.0"
+dependencies = [
+ "take-until",
+]
+
+[[package]]
+name = "take-until"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b4e17d8598067a8c134af59cd33c1c263470e089924a11ab61cf61690919fe3b"
diff --git a/2022/rust/day08/Cargo.toml b/2022/rust/day08/Cargo.toml
new file mode 100644
index 0000000..d2e406b
--- /dev/null
+++ b/2022/rust/day08/Cargo.toml
@@ -0,0 +1,9 @@
+[package]
+name = "day08"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+take-until = "0.1.0"
diff --git a/2022/rust/day08/src/main.rs b/2022/rust/day08/src/main.rs
new file mode 100644
index 0000000..4c53e14
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+++ b/2022/rust/day08/src/main.rs
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+use std::env;
+use std::fs;
+
+#[derive(Debug)]
+struct Tree {
+    height: i32,
+    visible: bool,
+    scenic: i32
+}
+
+#[allow(unused_parens)]
+fn main() {
+    let args = env::args().nth(1).expect("missing input");
+    let input = fs::read_to_string(args).unwrap();
+    let mut forest: Vec<Vec<Tree>> = input.trim().split("\n")
+        .map(|x| x.chars()
+            .map(|x| Tree {
+                height: x.to_digit(10).unwrap() as i32,
+                visible: false,
+                scenic: 1
+            }).collect()).collect();
+
+    let mut sum = 0;
+    let mut max = 0;
+    let len = forest.len();
+
+    // not thrilled with this code.
+    for i in 0 .. forest.len() {
+        let mut min = (-1, -1, -1, -1);
+        for j in 0 .. forest.len() {
+            let k = forest[0].len() - 1 - j;
+
+            if forest[i][j].height > min.0 {
+                min.0 = forest[i][j].height;
+                if !forest[i][j].visible {
+                    sum += 1;
+                }
+                forest[i][j].visible = true;
+            }
+            if forest[i][k].height > min.1 {
+                min.1 = forest[i][k].height;
+                if !forest[i][k].visible {
+                    sum += 1;
+                }
+                forest[i][k].visible = true;
+            }
+            if forest[j][i].height > min.2 {
+                min.2 = forest[j][i].height;
+                if !forest[j][i].visible {
+                    sum += 1;
+                }
+                forest[j][i].visible = true;
+            }
+            if forest[k][i].height > min.3 {
+                min.3 = forest[k][i].height;
+                if !forest[k][i].visible {
+                    sum += 1;
+                }
+                forest[k][i].visible = true;
+            }
+
+            let min = forest[i][j].height;
+            forest[i][j].scenic *= gaze(&forest, (i..=i), (j+1..len), min);
+            forest[i][j].scenic *= gaze(&forest, (i+1..len), (j..=j), min);
+            forest[i][j].scenic *= gaze(&forest, (i..=i), (0..j).rev(), min);
+            forest[i][j].scenic *= gaze(&forest, (0..i).rev(), (j..=j), min);
+
+            if forest[i][j].scenic > max {
+                max = forest[i][j].scenic;
+            }
+
+        }
+    }
+    println!("{}", sum);
+    println!("{}", max);
+}
+
+// bluh why are range and rangeinclusive separate types
+// bluhhh why are types not directly generic-able
+// bluhhhhhh https://kaylynn.gay/blog/post/rust_ranges_and_suffering
+
+// all things considered i'm happy with this function
+// considering how many Interesting behaviors of rust i ran into on the way
+fn gaze(forest: &Vec<Vec<Tree>>, x: impl Iterator<Item=usize>,
+        y: impl Iterator<Item=usize> + Clone, min: i32) -> i32 {
+    let mut count = 0;
+    for i in x {
+        for j in y.clone() {
+            count += 1;
+            if forest[i][j].height >= min {
+                return count;
+            }
+        }
+    }
+    return count;
+}