20240709 Finished

src/problem/mod.rs

@@ -171,3 +171,4 @@ mod p46_permutations;
 mod p39_combination_sum;
 mod p22_generate_parentheses;
 mod p79_word_search;
+mod p108_convert_sorted_array_to_binary_search_tree;

src/problem/p108_convert_sorted_array_to_binary_search_tree.rs

@@ -0,0 +1,70 @@
+/**
+ * [108] Convert Sorted Array to Binary Search Tree
+ */
+pub struct Solution {}
+
+use crate::util::tree::{TreeNode, to_tree};
+
+// submission codes start here
+
+// Definition for a binary tree node.
+// #[derive(Debug, PartialEq, Eq)]
+// pub struct TreeNode {
+//   pub val: i32,
+//   pub left: Option<Rc<RefCell<TreeNode>>>,
+//   pub right: Option<Rc<RefCell<TreeNode>>>,
+// }
+//
+// impl TreeNode {
+//   #[inline]
+//   pub fn new(val: i32) -> Self {
+//     TreeNode {
+//       val,
+//       left: None,
+//       right: None
+//     }
+//   }
+// }
+use std::rc::Rc;
+use std::cell::RefCell;
+impl Solution {
+    pub fn sorted_array_to_bst(nums: Vec<i32>) -> Option<Rc<RefCell<TreeNode>>> {
+        Some(Self::array_to_bst(&nums[..]))
+    }
+    
+    fn array_to_bst(array: &[i32]) -> Rc<RefCell<TreeNode>> {
+        let length = array.len();
+        
+        if length == 1 {
+            return Rc::new(RefCell::new(TreeNode::new(array[0])));
+        }
+        
+        let middle = length / 2;
+        
+        let node = Rc::new(RefCell::new(TreeNode::new(array[middle])));
+        
+        if middle != 0 {
+            // 左边
+            let left = &array[..middle];
+            node.borrow_mut().left = Some(Self::array_to_bst(left));
+        }
+        
+        if middle != length - 1 {
+            let right = &array[middle + 1..];
+            node.borrow_mut().right = Some(Self::array_to_bst(right));
+        }
+        
+        return node;
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_108() {
+    }
+}