Added 2022, first few problems

3 files changed, 38 insertions, 0 deletions

diff --git a/2022/06/a.rs b/2022/06/a.rs
new file mode 100644
index 0000000..996f9a5
--- /dev/null
+++ b/2022/06/a.rs
@@ -0,0 +1,9 @@
+mod common;
+use common::*;
+
+fn main() {
+    let mut line = String::new();
+    std::io::stdin().read_line(&mut line).unwrap();
+    let i = first_index_n_distinct(line.as_bytes(), 4) + 1;
+    println!("{i}");
+}
diff --git a/2022/06/b.rs b/2022/06/b.rs
new file mode 100644
index 0000000..78d2703
--- /dev/null
+++ b/2022/06/b.rs
@@ -0,0 +1,9 @@
+mod common;
+use common::*;
+
+fn main() {
+    let mut line = String::new();
+    std::io::stdin().read_line(&mut line).unwrap();
+    let i = first_index_n_distinct(line.as_bytes(), 14) + 1;
+    println!("{i}");
+}
diff --git a/2022/06/common.rs b/2022/06/common.rs
new file mode 100644
index 0000000..ed5360c
--- /dev/null
+++ b/2022/06/common.rs
@@ -0,0 +1,20 @@
+fn all_distinct<T: PartialEq>(a: &[T]) -> bool {
+    for i in 0..a.len() {
+        for j in i+1..a.len() {
+            if a[i] == a[j] {
+                return false;
+            }
+        }
+    }
+    return true;
+}
+
+pub fn first_index_n_distinct(a: &[u8], n: usize) -> usize {
+    assert!(n > 0, "{} must be greater than 0", n);
+    for i in 0..a.len()-n+1 {
+        if all_distinct(&a[i..i+n]) {
+            return i+n-1;
+        }
+    }
+    panic!("Cannot find {} distinct in a row", n);
+}