feat: add more

Author: gengjiawen

stack/_0022_generate_parentheses.rs

@@ -0,0 +1,64 @@
+// https://leetcode.com/problems/generate-parentheses
+//
+// Given `n` pairs of parentheses, write a function to _generate all combinations of well-formed parentheses_.
+//
+// **Example 1:**
+//
+// ```
+// **Input:** n = 3
+// **Output:** ["((()))","(()())","(())()","()(())","()()()"]
+// ```
+//
+// **Example 2:**
+//
+// ```
+// **Input:** n = 1
+// **Output:** ["()"]
+// ```
+//
+// **Constraints:**
+//
+// *   `1 <= n <= 8`
+
+pub fn generate_parenthesis(n: i32) -> Vec<String> {
+    let mut res = vec![];
+    fn backtrack(
+        n: i32,
+        open_count: i32,
+        close_count: i32,
+        cur: &mut String,
+        res: &mut Vec<String>,
+    ) {
+        if open_count == n && close_count == n {
+            res.push(cur.clone());
+            return;
+        }
+        if open_count < n {
+            cur.push('(');
+            backtrack(n, open_count + 1, close_count, cur, res);
+            cur.pop();
+        }
+        if close_count < open_count {
+            cur.push(')');
+            backtrack(n, open_count, close_count + 1, cur, res);
+            cur.pop();
+        }
+    }
+
+    backtrack(n, 0, 0, &mut String::new(), &mut res);
+    return res;
+}
+
+#[test]
+pub fn t1() {
+    assert_eq!(
+        generate_parenthesis(3),
+        vec![
+            "((()))".to_string(),
+            "(()())".to_string(),
+            "(())()".to_string(),
+            "()(())".to_string(),
+            "()()()".to_string(),
+        ]
+    );
+}

stack/lib.rs

@@ -1,5 +1,6 @@
 #![allow(dead_code)]
 
 mod _0020_valid_parentheses;
+mod _0022_generate_parentheses;
 mod _0155_min_stack;
 mod _1598_crawler_log_folder;