day14

1 files changed, 147 insertions, 0 deletions

diff --git a/2024/day14.rs b/2024/day14.rs
new file mode 100644
index 0000000..836df78
--- /dev/null
+++ b/2024/day14.rs
@@ -0,0 +1,147 @@
+#![allow(dead_code)]
+#![allow(unused_variables)]
+#![allow(unused_mut)]
+use std::env;
+use std::fs::File;
+use std::io::Read;
+
+fn sim(w: i64, h: i64, mut pv: Vec<(i64, i64, i64, i64)>) -> Vec<(i64, i64, i64, i64)> {
+    for i in 0..pv.len() {
+        let (mut px, mut py, vx, vy) = pv[i];
+        px += vx;
+        py += vy;
+        if px < 0 {
+            px += w;
+        }
+        if px >= w {
+            px -= w;
+        }
+        if py < 0 {
+            py += h;
+        }
+        if py >= h {
+            py -= h;
+        }
+        pv[i] = (px, py, vx, vy);
+    }
+    pv
+}
+
+fn main() {
+    let args: Vec<String> = env::args().collect();
+    let filename = if args.len() == 1 {
+        "in/".to_owned() + args[0].split('/').last().unwrap() + ".pzl"
+    } else {
+        args[1].clone()
+    };
+    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 pv: Vec<(i64, i64, i64, i64)> = Vec::new();
+    for line in lines {
+        let (s, rest) = line.split_once("p=").unwrap();
+        let (s, rest) = rest.split_once(",").unwrap();
+        let px = s.parse().unwrap();
+
+        let (s, rest) = rest.split_once(" ").unwrap();
+        let py = s.parse().unwrap();
+
+        let (s, rest) = rest.split_once("v=").unwrap();
+        let (s, rest) = rest.split_once(",").unwrap();
+        let vx = s.parse().unwrap();
+
+        let vy = rest.parse().unwrap();
+
+        pv.push((px, py, vx, vy));
+    }
+
+    let w = 101;
+    let h = 103;
+    //let w = 11;
+    //let h = 7;
+
+    let pv_orig = pv.clone();
+    for i in 1..=100 {
+        pv = sim(w, h, pv);
+    }
+    let q1 = pv
+        .clone()
+        .into_iter()
+        .filter(|(px, py, vx, vy)| *px > w / 2 && *py < h / 2)
+        .collect::<Vec<_>>()
+        .len();
+    let q2 = pv
+        .clone()
+        .into_iter()
+        .filter(|(px, py, vx, vy)| *px < w / 2 && *py < h / 2)
+        .collect::<Vec<_>>()
+        .len();
+    let q3 = pv
+        .clone()
+        .into_iter()
+        .filter(|(px, py, vx, vy)| *px > w / 2 && *py > h / 2)
+        .collect::<Vec<_>>()
+        .len();
+    let q4 = pv
+        .clone()
+        .into_iter()
+        .filter(|(px, py, vx, vy)| *px < w / 2 && *py > h / 2)
+        .collect::<Vec<_>>()
+        .len();
+    let res1 = q1 * q2 * q3 * q4;
+
+    let mut res2 = 0;
+    pv = pv_orig.clone();
+    for i in 1.. {
+        pv = sim(w, h, pv);
+        //println!("{:?}", pv);
+        if pv == pv_orig {
+            println!("END OF SIM {}", i);
+            break;
+        }
+
+        let mut diag1 = 0;
+        for i in 0..pv.len() {
+            let (px, py, vx, vy) = pv[i];
+            if py < -px * h / (w / 2) + h {
+                diag1 += 1;
+            }
+        }
+
+        let mut diag2 = 0;
+        for i in 0..pv.len() {
+            let (px, py, vx, vy) = pv[i];
+            if py < px * h / (w / 2) - h {
+                diag2 += 1;
+            }
+        }
+
+        //if diag1 < 110 && diag2 < 110 {
+        if i == 7916 {
+            res2 = i;
+            println!("{}", i);
+            let mut m: Vec<Vec<i64>> = vec![vec![0; w as usize]; h as usize];
+            for i in 0..pv.len() {
+                let (px, py, vx, vy) = pv[i];
+                m[py as usize][px as usize] += 1;
+            }
+            for y in 0..m.len() {
+                for x in 0..m[0].len() {
+                    if m[y][x] == 0 {
+                        print!(" ");
+                    } else {
+                        print!("{}", m[y][x]);
+                    }
+                }
+                println!();
+            }
+        }
+    }
+
+    println!("res1: {}", res1);
+    println!("res2: {}", res2);
+    assert_eq!(res1, 221142636);
+    assert_eq!(res2, 7916);
+}