Solution for day 9

day09/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "day09"
+version = "0.1.0"
+authors = ["inga-lovinde <52715130+inga-lovinde@users.noreply.github.com>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

day09/src/main.rs

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+use std::collections::HashMap;
+use std::io::{self, BufRead};
+
+const BLOCK_SIZE: usize = 25;
+
+fn main() {
+    let stdin = io::stdin();
+    let numbers: Vec<u128> = stdin.lock().lines()
+        .map(|line| line.unwrap().parse().unwrap())
+        .collect();
+
+    let mut part1_key = 0;
+    for i in BLOCK_SIZE..numbers.len() {
+        let mut found: bool = false;
+        for j in i-BLOCK_SIZE..i {
+            for k in j+1..i {
+                if numbers[j] + numbers[k] == numbers[i] {
+                    found = true;
+                }
+            }
+        }
+
+        if !found {
+            part1_key = i;
+            break;
+        }
+    }
+
+    println!("{}", numbers[part1_key]);
+
+    for i in 0..part1_key {
+        let mut sum = 0u128;
+        let mut smallest = u128::MAX;
+        let mut largest = u128::MIN;
+        for j in i..part1_key {
+            sum += numbers[j];
+            smallest = u128::min(smallest, numbers[j]);
+            largest = u128::max(largest, numbers[j]);
+            if sum == numbers[part1_key] {
+                println!("{} ({},{})", smallest + largest, i, j);
+                return;
+            }
+        }
+
+    }
+}