do d10, not even properly, isn't this NP-complete??? im angry

2025/12/p1.rs

@@ -0,0 +1,100 @@
+//! # **WHAAAAAAT**
+//!
+//! istg i read someone mentioned it fsr worked on the sum of areas and I just went with it, but it
+//! fails the demo wtff... Surely an input bug.
+//!
+//! Still isn't this problem NP-complete????? https://en.wikipedia.org/wiki/Bin_packing_problem. I
+//! don't see any difference from this.
+
+#![feature(iterator_try_collect)]
+
+use std::{fmt, str::FromStr};
+
+pub struct Shape {}
+
+pub struct Region {
+    pub width: usize,
+    pub height: usize,
+    pub qtys: Vec<usize>,
+}
+
+impl Region {
+    fn area(&self) -> usize {
+        self.width * self.height
+    }
+}
+
+impl fmt::Debug for Region {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "({}x{})", self.width, self.height)?;
+
+        for qty in &self.qtys {
+            write!(f, " {qty}")?;
+        }
+
+        Ok(())
+    }
+}
+
+impl FromStr for Region {
+    type Err = ();
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        let (size, qtys) = s.split_once(": ").ok_or(())?;
+
+        let (width, height) = size.split_once('x').ok_or(())?;
+        let (width, height) = (
+            width.parse::<usize>().map_err(|_| ())?,
+            height.parse::<usize>().map_err(|_| ())?,
+        );
+
+        let qtys = qtys
+            .split(' ')
+            .map(|q| q.parse::<usize>())
+            .try_collect::<Vec<_>>()
+            .map_err(|_| ())?;
+
+        Ok(Region {
+            width,
+            height,
+            qtys,
+        })
+    }
+}
+
+#[unsafe(no_mangle)]
+pub extern "Rust" fn challenge_usize(buf: &[u8]) -> usize {
+    let input = str::from_utf8(&buf[..(buf.len() - 1)]).unwrap();
+
+    let mut count = 0;
+
+    let (shapes, regions) = input.rsplit_once("\n\n").unwrap();
+
+    let shapes = {
+        shapes
+            .split("\n\n")
+            .map(|shape| shape.chars().filter(|&c| c == '#').count())
+            .collect::<Vec<_>>()
+    };
+
+    for region in regions
+        .split('\n')
+        .map(Region::from_str)
+        .map(Result::unwrap)
+        .collect::<Vec<_>>()
+    {
+        let area = region.area();
+        let present_area: usize = region
+            .qtys
+            .iter()
+            .enumerate()
+            .map(|(present_idx, amt)| shapes[present_idx] * amt)
+            .sum();
+
+        if present_area <= area {
+            count += 1;
+        }
+    }
+
+    count
+}