DeaDvey d3 optimisations & danmax

2025/3/danmax/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "danmax"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]

2025/3/danmax/src/main.rs

@@ -0,0 +1,18 @@
+fn main() {
+    let raw = std::fs::read_to_string("../large.txt").unwrap();
+    let start = std::time::Instant::now();
+    let mut banks = raw.split('\n').collect::<Vec<&str>>();
+    banks.pop();
+    let mut sol = 0;
+    for bank in banks {
+        let batteries = bank.chars().map(|x| (x as u8) - 48).collect::<Vec<u8>>();
+        let mut combos = vec![];
+        for i in 0..batteries.len() - 1 {
+            let num = (batteries[i] * 10) + batteries[(i + 1)..batteries.len()].iter().max().unwrap();
+            combos.push(num);
+        }
+        sol += *combos.iter().max().unwrap() as u64;
+    }
+    let end = start.elapsed();
+    dbg!(sol, end);
+}

2025/3/deadvey/src/main.rs

@@ -1,5 +1,6 @@
 use std::fs;
 use std::time::Instant;
+use std::ptr;
 
 fn algorithm(banks: &Vec<&str>) -> (u64, u64)
 {
@@ -11,39 +12,43 @@ fn algorithm(banks: &Vec<&str>) -> (u64, u64)
         let mut joltages: [u64; 12] = [0; 12];
         let mut highest: u64 = 0;
         let mut overall_index = 0;
+        // part 2
         for i in 0..=11 {
             for joltage in bank[prev_index..(bank_length-(11-i))].bytes() {
                 overall_index += 1;
-                if joltage == 57 {
-                    highest = 9;
+                if joltage as u64 > highest {
                     prev_index = overall_index;
-                    break;
+                    unsafe {
+                        ptr::write(&mut highest as *mut u64, joltage as u64);
                     }
-                let joltage_int = joltage ^ 48; // ASCII mask using XOR (^)
-                if joltage_int as u64 > highest {
-                    prev_index = overall_index;
-                    highest = joltage_int as u64;
+                    if joltage == 57 { break; }
                 }
             }
             overall_index = prev_index;
-            joltages[i] = highest as u64;
+            joltages[i] = highest ^ 48;
             highest = 0;
         }
         prev_index = 0;
         for i in 0..=10 {
             if joltages[i] > highest.into() {
-                highest = joltages[i] as u64;
+                unsafe {
+                    ptr::write(&mut highest as *mut u64, joltages[i] as u64);
+                }
                 prev_index = i+1;
+                if joltages[i] == 9 { break; }
             }
         }
-        total1 += (highest * 10) as u64;
+        total1 += highest * 10;
         highest = 0;
         for i in prev_index..=11 {
             if joltages[i] > highest.into() {
-                highest = joltages[i] as u64;
+                unsafe {
+                    ptr::write(&mut highest as *mut u64, joltages[i] as u64);
+                }
+                if joltages[i] == 9 { break; }
             }
         }
-        total1 += (highest) as u64;
+        total1 += highest;
         total2 += joltages[0] * 10_u64.pow(11)
             + joltages[1] * 10_u64.pow(10)
             + joltages[2] * 10_u64.pow(9)
@@ -66,28 +71,28 @@ fn algorithm(banks: &Vec<&str>) -> (u64, u64)
 // 234234234234278
 // 818181911112111
 fn main() {
-    let start = Instant::now();
     let file_contents: String = fs::read_to_string("../large.txt").unwrap();
+    let start = Instant::now();
+
     let mut banks: Vec<&str> = file_contents
         .split('\n')
         .collect::<Vec<&str>>();
     banks.pop();
-    let file_read = start.elapsed();
+    let preamble = start.elapsed();
 
     let (total1, total2) = algorithm(&banks);
     let end = start.elapsed();
 
-    let end = start.elapsed();
     println!("part1: {total1}");
     println!("part2: {total2}");
     println!("Times:
-    File read:          {:.2?}
+    Preamble:           {:.2?}
     Loop:               {:.2?}
-    Avg time per pair:  {:.2?}
+    Avg time per bank:  {:.2?}
     Total:              {:.4?}
     ",
-    file_read,
-    end-file_read,
-    (end-file_read)/(10000).try_into().unwrap(),
+    preamble,
+    end-preamble,
+    (end-preamble)/(10000).try_into().unwrap(),
     end);
 }