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Author: rahul003t

0div-idbig-omega-company-tagsdiv-idbig-omega-topbardiv-classcompanytagscontainer-styleoverflow-x-scroll-flex-wrap-nowrap-div-classcompanytagscontainer-tag-stylebackground-color-rgba0-10-32-005-divfacebook-divdiv-classcompanytagscontainer-tagoccurence2-div-div-divdiv-classcompanytagscontainer-chevrondivsvg-version11-idicon-xmlnshttp-wwww3org-2000-svg-xmlns-xlinkhttp-wwww3org-1999-xlink-x0px-y0px-viewbox0-0-32-32-fill4087f1-xml-spacepreserve-stylewidth-20px-polygon-points16-22-6-12-74-106-16-192-246-106-26-12-polygonrect-id-x3c-transparent-rectangle-x3e-classst0-fillnone-width32-height32-rect-svg-div-div-div-div606-construct-string-from-binary-tree/0div-idbig-omega-company-tagsdiv-idbig-omega-topbardiv-classcompanytagscontainer-styleoverflow-x-scroll-flex-wrap-nowrap-div-classcompanytagscontainer-tag-stylebackground-color-rgba0-10-32-005-divfacebook-divdiv-classcompanytagscontainer-tagoccurence2-div-div-divdiv-classcompanytagscontainer-chevrondivsvg-version11-idicon-xmlnshttp-wwww3org-2000-svg-xmlns-xlinkhttp-wwww3org-1999-xlink-x0px-y0px-viewbox0-0-32-32-fill4087f1-xml-spacepreserve-stylewidth-20px-polygon-points16-22-6-12-74-106-16-192-246-106-26-12-polygonrect-id-x3c-transparent-rectangle-x3e-classst0-fillnone-width32-height32-rect-svg-div-div-div-div606-construct-string-from-binary-tree.java

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+/**
+ * Definition for a binary tree node.
+ * public class TreeNode {
+ *     int val;
+ *     TreeNode left;
+ *     TreeNode right;
+ *     TreeNode() {}
+ *     TreeNode(int val) { this.val = val; }
+ *     TreeNode(int val, TreeNode left, TreeNode right) {
+ *         this.val = val;
+ *         this.left = left;
+ *         this.right = right;
+ *     }
+ * }
+ */
+class Solution {
+    public String tree2str(TreeNode t) {
+        StringBuilder res = new StringBuilder();
+        dfs(t, res);
+        return res.toString();
+    }
+
+    public static void dfs(TreeNode t, StringBuilder res) {
+        if (t == null)
+            return;
+        res.append(String.valueOf(t.val));
+        if (t.left == null && t.right == null)
+            return;
+        res.append('(');
+        dfs(t.left, res);
+        res.append(')');
+        if (t.right != null) {
+            res.append('(');
+            dfs(t.right, res);
+            res.append(')');
+        }
+    }
+}