rust leetcode

rust-leetcode/README.md

@@ -304,17 +304,65 @@ impl Solution {
 * 从尾到头打印链表
 ```rust
 impl Solution {
-        pub fn reverse_print(head: Option<Box<ListNode>>) -> Vec<i32> {
-            let mut ret = Vec::<i32>::new();
-            let mut node = head.as_ref();
-            loop {
-                if let Some(root) = node {
-                    ret.push(root.val);
-                    node = root.next.as_ref();
-                } else { break }
+    pub fn reverse_print(head: Option<Box<ListNode>>) -> Vec<i32> {
+        let mut ret = Vec::<i32>::new();
+        let mut node = head.as_ref();
+        loop {
+            if let Some(root) = node {
+                ret.push(root.val);
+                node = root.next.as_ref();
+            } else { break }
+        }
+        ret.reverse();
+        ret
+    }
+}
+```
+* 二叉搜索树的范围和
+```rust
+impl Solution {
+    pub fn range_sum_bst(root: Option<Rc<RefCell<TreeNode>>>, l: i32, r: i32) -> i32 {
+        let mut ret = 0;
+        let mut nodes = VecDeque::new();
+        nodes.push_back(root);
+        while !nodes.is_empty() {
+            let tmp = nodes.pop_back();
+            if let Some(node) = tmp {
+                if let Some(n) = node {
+                    if n.try_borrow().unwrap().val >= l && n.try_borrow().unwrap().val <= r {
+                        ret += n.try_borrow().unwrap().val
+                    }
+                    //满足条件继续查找
+                    if n.try_borrow().unwrap().val > l {
+                        nodes.push_back(n.try_borrow().unwrap().left.clone());
+                    }
+                    if n.try_borrow().unwrap().val < r {
+                        nodes.push_back(n.try_borrow().unwrap().right.clone());
+                    }
+                }
             }
-            ret.reverse();
-            ret
         }
+        ret
+    }
+
+    pub fn range_sum_bst2(root: Option<Rc<RefCell<TreeNode>>>, l: i32, r: i32) -> i32 {
+        let mut ret = 0;
+        fn bst(root: Option<Rc<RefCell<TreeNode>>>, l: i32, r: i32, ret: &mut i32) {
+            if let Some(node) = root {
+                if node.try_borrow().unwrap().val >= l && node.try_borrow().unwrap().val <= r {
+                    *ret += node.try_borrow().unwrap().val
+                }
+                if node.try_borrow().unwrap().val > l {
+                    bst(node.try_borrow().unwrap().left.clone(), l, r, ret)
+                }
+                if node.try_borrow().unwrap().val < r {
+                    bst(node.try_borrow().unwrap().right.clone(), l, r, ret)
+                }
+            }
+        }
+        //可变借用，修改外函数的变量ret
+        bst(root, l, r, &mut ret);
+        ret
+    }
 }
 ```

rust-leetcode/src/Solution.rs

@@ -488,7 +488,7 @@ fn interview_06() {
                 if let Some(root) = node {
                     ret.push(root.val);
                     node = root.next.as_ref();
-                } else { break }
+                } else { break; }
             }
             ret.reverse();
             ret
@@ -501,6 +501,58 @@ fn interview_06() {
     println!("{:?}", ret);
 }
 
+///二叉搜索树的范围和
+fn leetcode_938() {
+    println!("leetcode_938");
+    use std::rc::Rc;
+    use std::cell::RefCell;
+    impl Solution {
+        pub fn range_sum_bst(root: Option<Rc<RefCell<TreeNode>>>, l: i32, r: i32) -> i32 {
+            let mut ret = 0;
+            let mut nodes = VecDeque::new();
+            nodes.push_back(root);
+            while !nodes.is_empty() {
+                let tmp = nodes.pop_back();
+                if let Some(node) = tmp {
+                    if let Some(n) = node {
+                        if n.try_borrow().unwrap().val >= l && n.try_borrow().unwrap().val <= r {
+                            ret += n.try_borrow().unwrap().val
+                        }
+                        //满足条件继续查找
+                        if n.try_borrow().unwrap().val > l {
+                            nodes.push_back(n.try_borrow().unwrap().left.clone());
+                        }
+                        if n.try_borrow().unwrap().val < r {
+                            nodes.push_back(n.try_borrow().unwrap().right.clone());
+                        }
+                    }
+                }
+            }
+            ret
+        }
+
+        pub fn range_sum_bst2(root: Option<Rc<RefCell<TreeNode>>>, l: i32, r: i32) -> i32 {
+            let mut ret = 0;
+            fn bst(root: Option<Rc<RefCell<TreeNode>>>, l: i32, r: i32, ret: &mut i32) {
+                if let Some(node) = root {
+                    if node.try_borrow().unwrap().val >= l && node.try_borrow().unwrap().val <= r {
+                        *ret += node.try_borrow().unwrap().val
+                    }
+                    if node.try_borrow().unwrap().val > l {
+                        bst(node.try_borrow().unwrap().left.clone(), l, r, ret)
+                    }
+                    if node.try_borrow().unwrap().val < r {
+                        bst(node.try_borrow().unwrap().right.clone(), l, r, ret)
+                    }
+                }
+            }
+            //可变借用，修改外函数的变量ret
+            bst(root, l, r, &mut ret);
+            ret
+        }
+    }
+}
+
 ///所有方法调用
 pub fn solutions() {
     interview_58_2();
@@ -518,6 +570,7 @@ pub fn solutions() {
     interview_05();
     leetcode_1221();
     interview_06();
+    leetcode_938();
 }
 
 fn print_vec(nums: Vec<i32>) {