From f0ba102a70bebd3a87b88644d0d254853d006e0a Mon Sep 17 00:00:00 2001
From: jackfiled <xcrenchangjun@outlook.com>
Date: Tue, 29 Oct 2024 11:11:33 +0800
Subject: [PATCH] 20241029 finished.

---
 src/problem/mod.rs                            |  2 +
 ...e_binary_strings_without_adjacent_zeros.rs | 49 +++++++++++++++++++
 2 files changed, 51 insertions(+)
 create mode 100644 src/problem/p3211_generate_binary_strings_without_adjacent_zeros.rs

diff --git a/src/problem/mod.rs b/src/problem/mod.rs
index 4a16365..1c2568a 100644
--- a/src/problem/mod.rs
+++ b/src/problem/mod.rs
@@ -282,3 +282,5 @@ mod p3181_maximum_total_reward_using_operations_ii;
 mod p684_redundant_connection;
 
 mod p685_redundant_connection_ii;
+
+mod p3211_generate_binary_strings_without_adjacent_zeros;
diff --git a/src/problem/p3211_generate_binary_strings_without_adjacent_zeros.rs b/src/problem/p3211_generate_binary_strings_without_adjacent_zeros.rs
new file mode 100644
index 0000000..00862f5
--- /dev/null
+++ b/src/problem/p3211_generate_binary_strings_without_adjacent_zeros.rs
@@ -0,0 +1,49 @@
+/**
+ * [3211] Generate Binary Strings Without Adjacent Zeros
+ */
+pub struct Solution {}
+
+// submission codes start here
+
+impl Solution {
+    pub fn valid_strings(n: i32) -> Vec<String> {
+        let n = n as usize;
+        let mut result = Vec::new();
+        let mut str = vec!['0'; n];
+
+        Self::dfs(0, false, &mut str, &mut result);
+
+        result
+    }
+
+    fn dfs(i: usize, last_zero: bool, str: &mut Vec<char>, result: &mut Vec<String>) {
+        if i >= str.len() {
+            result.push(str.iter().collect());
+            return;
+        }
+
+        if !last_zero {
+            str[i] = '0';
+            Self::dfs(i + 1, true, str, result);
+        }
+
+        str[i] = '1';
+        Self::dfs(i + 1, false, str, result);
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_3211() {
+        assert_eq!(
+            vec_string!("010", "011", "101", "110", "111"),
+            Solution::valid_strings(3)
+        );
+        assert_eq!(vec_string!("0", "1"), Solution::valid_strings(1));
+    }
+}