day14

1 files changed, 133 insertions, 0 deletions

diff --git a/2023/day14.rs b/2023/day14.rs
new file mode 100644
index 0000000..cb5ea93
--- /dev/null
+++ b/2023/day14.rs
@@ -0,0 +1,133 @@
+#![allow(dead_code)]
+use std::collections::HashMap;
+use std::fs::File;
+use std::io::Read;
+
+#[derive(Hash, Eq, Debug, PartialEq, Clone, Copy)]
+enum Spc {
+    Rol,
+    Fix,
+    Non,
+}
+
+fn new_north_y(x: usize, y: usize, m: &Vec<Vec<Spc>>) -> usize {
+    for yi in (0..y).rev() {
+        if m[yi][x] != Spc::Non {
+            return yi + 1;
+        }
+    }
+    // reached the end of map
+    return 0;
+}
+
+fn rotate_positive(m: Vec<Vec<Spc>>) -> Vec<Vec<Spc>> {
+    let mut out: Vec<Vec<Spc>> = Vec::new();
+    for i in (0..m[0].len()).rev() {
+        let mut r: Vec<Spc> = Vec::new();
+        for j in 0..m.len() {
+            r.push(m[j][i]);
+        }
+        out.push(r);
+    }
+    out
+}
+
+fn print_m(m: &Vec<Vec<Spc>>) {
+    for i in 0..m.len() {
+        for j in 0..m[0].len() {
+            let a = match m[i][j] {
+                Spc::Rol => 'O',
+                Spc::Fix => '#',
+                Spc::Non => '.',
+            };
+            print!("{}", a);
+        }
+        println!();
+    }
+    println!();
+}
+
+fn calc_load(m: &Vec<Vec<Spc>>) -> usize {
+    let mut load = 0;
+    for i in 0..m[0].len() {
+        for j in 0..m.len() {
+            if m[j][i] == Spc::Rol {
+                load += m.len() - j;
+            }
+        }
+    }
+    load
+}
+
+fn main() {
+    // let filename = "in/day14.ref";
+    let filename = "in/day14.pzl";
+
+    let mut f = File::open(filename).expect("cannot open file");
+    let mut content = String::new();
+    f.read_to_string(&mut content).expect("cannot read file");
+    let lines = content.trim_end().split('\n');
+
+    let mut m: Vec<Vec<Spc>> = Vec::new();
+    for line in lines {
+        let mut r: Vec<Spc> = Vec::new();
+        for c in line.chars() {
+            let s = match c {
+                'O' => Spc::Rol,
+                '#' => Spc::Fix,
+                '.' => Spc::Non,
+                _ => panic!(),
+            };
+            r.push(s);
+        }
+        m.push(r);
+    }
+    let mut m2 = m.clone();
+
+    for i in 0..m[0].len() {
+        for j in 0..m.len() {
+            if m[j][i] == Spc::Rol {
+                let new_y = new_north_y(i, j, &m);
+                m[j][i] = Spc::Non;
+                m[new_y][i] = Spc::Rol;
+            }
+        }
+    }
+    let res1 = calc_load(&m);
+
+    let mut mm: HashMap<Vec<Vec<Spc>>, u64> = HashMap::new();
+    let mut cm: HashMap<u64, usize> = HashMap::new();
+
+    let mut c0 = 0;
+    let mut c1 = 0;
+    for cycle in 0..1000000000 {
+        for _ in 0..4 {
+            for i in 0..m2[0].len() {
+                for j in 0..m2.len() {
+                    if m2[j][i] == Spc::Rol {
+                        let new_y = new_north_y(i, j, &m2);
+                        m2[j][i] = Spc::Non;
+                        m2[new_y][i] = Spc::Rol;
+                    }
+                }
+            }
+            m2 = rotate_positive(m2);
+            m2 = rotate_positive(m2);
+            m2 = rotate_positive(m2);
+        }
+        if let Some(cycle_start) = mm.insert(m2.clone(), cycle) {
+            c0 = cycle_start;
+            c1 = cycle;
+            break;
+        }
+        cm.insert(cycle, calc_load(&m2));
+    }
+
+    // ne vem zakaj rabis ta - 1
+    let res2 = cm[&((1000000000 - c0 - 1) % (c1 - c0) + c0)];
+
+    println!("res1: {}", res1);
+    println!("res2: {}", res2);
+    assert_eq!(res1, 103333);
+    assert_eq!(res2, 97241);
+}