[TASK] Solved day 9 + added benchmarking options to the main method

src/main.rs

@@ -10,37 +10,66 @@ mod day5;
 mod day6;
 mod day7;
 mod day8;
+mod day9;
+
+const MAX_DAY: u8 = 9;
+const BENCHMARK_AMOUNT: u32 = 100;
+
+fn solve(day: u8) {
+    match day {
+        1 => day1::solve(),
+        2 => day2::solve(),
+        3 => day3::solve(),
+        4 => day4::solve(),
+        5 => day5::solve(),
+        6 => day6::solve(),
+        7 => day7::solve(),
+        8 => day8::solve(),
+        9 => day9::solve(),
+        _ => println!("This day is not yet implemented")
+    }
+}
 
 fn main() {
 
-    let now = Instant::now();
 
     let args: Vec<String> = std::env::args().collect();
 
     let day_arg_idx = args.iter().position(|a| a == "-d");
-    if day_arg_idx.is_some() {
-        match args[day_arg_idx.unwrap() + 1].parse::<u8>().unwrap() {
-            1 => day1::solve(),
-            2 => day2::solve(),
-            3 => day3::solve(),
-            4 => day4::solve(),
-            5 => day5::solve(),
-            6 => day6::solve(),
-            7 => day7::solve(),
-            8 => day8::solve(),
-            _ => println!("This day is not yet implemented")
+    let single_day = day_arg_idx.is_some();
+    let day = if single_day { args[day_arg_idx.unwrap() + 1].parse::<u8>().unwrap() } else { 0 };
+
+    let benchmark = args.contains(&String::from("--bench")) || args.contains(&String::from("-b"));
+
+    let mut bench_results: Vec<u128> = Vec::new();
+
+    // This is essentially the warmup for the benchmark:
+    run_once(single_day, day, &mut bench_results);
+
+    if benchmark {
+        for _ in 0..BENCHMARK_AMOUNT {
+            run_once(single_day, day, &mut bench_results);
         }
-    } else {
-        // Solve all days:
-        day1::solve();
-        day2::solve();
-        day3::solve();
-        day4::solve();
-        day5::solve();
-        day6::solve();
-        day7::solve();
-        day8::solve();
     }
 
-    println!("Execution took {} μs", now.elapsed().as_micros());
+    let avg_runtime: u128 = bench_results.iter().sum::<u128>() / (bench_results.len() as u128);
+
+    println!("Execution took {} μs {}", avg_runtime, if benchmark { "on average" } else { "" });
 }
+
+fn run_once(single_day: bool, day: u8, bench_results: &mut Vec<u128>) {
+
+    let now  = Instant::now();
+    if single_day {
+        solve(day);
+    } else {
+        solve_all();
+    }
+    bench_results.push(now.elapsed().as_micros());
+}
+
+fn solve_all() {
+    for day in 1..(MAX_DAY + 1) {
+        solve(day);
+    }
+}