edit 111

Author: fishercoder1534

src/main/java/com/fishercoder/solutions/_111.java

@@ -5,48 +5,50 @@
 import java.util.LinkedList;
 import java.util.Queue;
 
-/**Given a binary tree, find its minimum depth.
-
- The minimum depth is the number of nodes along the shortest path from the root node down to the nearest leaf node.*/
+/**
+ * 111. Minimum Depth of Binary Tree
+ * Given a binary tree, find its minimum depth.
+ * The minimum depth is the number of nodes along the shortest path from the root node down to the nearest leaf node.
+ * */
 
 public class _111 {
-/**We can solve this problem using both BFS and DFS:
- * DFS is to visit every single root to leaf path and return the shortest one.
- * BFS is to visit every level and return whenever we find the first leaf node.*/
-    public int minDepth(TreeNode root) {
-        if(root == null) return 0;
-        int left = minDepth(root.left);
-        int right = minDepth(root.right);
-        if(left == 0) return right+1;
-        if(right == 0) return left+1;
-        return Math.min(left, right)+1;
-    }
-    
-    public static void main(String[] args){
-        _111 test = new _111();
-        TreeNode root = new TreeNode(1);
-        root.left = new TreeNode(2);
-        root.right = new TreeNode(3);
-        System.out.println(test.minDepth(root));
+    /**
+     * We can solve this problem using both BFS and DFS:
+     * DFS is to visit every single root to leaf path and return the shortest one.
+     * BFS is to visit every level and return whenever we find the first leaf node.
+     */
+
+    public static class DFSSolution {
+
+        public int minDepth(TreeNode root) {
+            if (root == null) return 0;
+            int left = minDepth(root.left);
+            int right = minDepth(root.right);
+            if (left == 0) return right + 1;
+            if (right == 0) return left + 1;
+            return Math.min(left, right) + 1;
+        }
+
     }
-    
-
-    public int minDepth_BFS(TreeNode root) {
-        if(root == null) return 0;
-        Queue<TreeNode> q = new LinkedList();
-        q.offer(root);
-        int level = 0;
-        while(!q.isEmpty()){
-            level++;
-            int size = q.size();
-            for(int i = 0; i < size; i++){
-                TreeNode curr = q.poll();
-                if(curr.left != null) q.offer(curr.left);
-                if(curr.right != null) q.offer(curr.right);
-                if(curr.left == null && curr.right == null) return level;
+
+    public static class BFSSolution {
+
+        public int minDepth_BFS(TreeNode root) {
+            if (root == null) return 0;
+            Queue<TreeNode> q = new LinkedList();
+            q.offer(root);
+            int level = 0;
+            while (!q.isEmpty()) {
+                level++;
+                int size = q.size();
+                for (int i = 0; i < size; i++) {
+                    TreeNode curr = q.poll();
+                    if (curr.left != null) q.offer(curr.left);
+                    if (curr.right != null) q.offer(curr.right);
+                    if (curr.left == null && curr.right == null) return level;
+                }
             }
+            return level;
         }
-        return level;
     }
-
 }