4 files changed, 47 insertions(+), 0 deletions(-)

M Cargo.lock
M Cargo.toml
A problem_008/Cargo.toml
A problem_008/src/main.rs

@@ 45,6 45,13 @@ dependencies = [
 ]
 
 [[package]]
+name = "problem_008"
+version = "0.1.0"
+dependencies = [
+ "common 0.1.0",
+]
+
+[[package]]
 name = "problem_009"
 version = "0.1.0"
 dependencies = [

@@ 7,6 7,7 @@ members = [
     "problem_005",
     "problem_006",
     "problem_007",
+    "problem_008",
     "problem_009",
     "problem_010",
     "problem_019",

@@ 0,0 1,8 @@
+[package]
+name = "problem_008"
+version = "0.1.0"
+authors = ["Jan Baudisch <dev@baudisch.xyz>"]
+edition = "2018"
+
+[dependencies]
+common = { path = "../common" }

@@ 0,0 1,31 @@
+use common::input;
+
+fn main() {
+    println!("[INPUT] number (multi-line):");
+    let input: Vec<String> = input::read_lines();
+    let digits = input
+        .iter()
+        .fold(String::new(), |string, part| string + part)
+        .chars()
+        .map(|digit| digit.to_digit(10).expect("Could not parse input!"))
+        .collect::<Vec<u32>>();
+
+    let mut largest = 0;
+
+    for start in 0..digits.len() - 12 {
+        let mut product = 1;
+
+        for i in 0..13 {
+            product *= u64::from(digits[start + i]);
+        }
+
+        if product > largest {
+            largest = product;
+        }
+    }
+
+    println!(
+        "[SOLUTION] largest product of 13 adjacent digits: {}",
+        largest
+    );
+}