Initial commitHEADmain

2 files changed, 36 insertions, 0 deletions

diff --git a/k-th-symbol-in-grammar/Cargo.toml b/k-th-symbol-in-grammar/Cargo.toml
new file mode 100644
index 0000000..4fccf4e
--- /dev/null
+++ b/k-th-symbol-in-grammar/Cargo.toml
@@ -0,0 +1,8 @@
+[package]
+name = "k-th-symbol-in-grammar"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
diff --git a/k-th-symbol-in-grammar/src/main.rs b/k-th-symbol-in-grammar/src/main.rs
new file mode 100644
index 0000000..5aaa24c
--- /dev/null
+++ b/k-th-symbol-in-grammar/src/main.rs
@@ -0,0 +1,28 @@
+fn main() {
+    println!("Hello, world!");
+    let tests = vec![
+        (1,1,0),
+        (2,1,0),
+        (2,2,1),
+        (30, 434991989, 0)
+    ];
+    for (n,k,o) in tests {
+        let result = Solution::kth_grammar(n,k);
+        println!("{n} {k} {result} {o}");
+    }
+}
+
+struct Solution;
+
+impl Solution {
+    pub fn kth_grammar(n: i32, k: i32) -> i32 {
+        let mut s: Vec<bool> = vec![false];
+        for _ in 0..n {
+            s = s.iter().flat_map(|x| match x {
+                false => [false,true],
+                true => [true,false]
+            }).collect::<Vec<_>>();
+        }
+        s[(k - 1) as usize] as i32
+    }
+}