Java 二叉搜索树：递归 toString
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时间：2020-08-13 02:17:23 来源:igfitidea点击:
Binary Search Tree: Recursive toString
提问by user2810123
It only prints out one item. It is suppose to print the contents of the tree in ascending order
它只打印出一项。假设按升序打印树的内容
public String toString()
{
return toString (_root);
}
private String toString(BSTnode root)
{
if (root == null)
return "";
toString(root._left);
toString(root._right);
return root._data.toString();
}
回答by RamonBoza
How do you want to show them?
你想如何向他们展示？
You need to append the Strings, for example.
例如，您需要附加字符串。
private String toString(BSTnode root)
{
StringBuilder builder = new StringBuilder();
if (root == null)
return "";
builder.append(toString(root._left));
builder.append(toString(root._right));
return builder.append(root._data.toString()).toString();
}
or just use a concatenation on strings.
或者只是在字符串上使用连接。
private String toString(BSTnode root)
{
String result = "";
if (root == null)
return "";
result += toString(root._left);
result += toString(root._right);
result += root._data.toString()
return result;
}
回答by Melvin
//Helper
public String toString(){
return "<" +toString(root) + ">";
}
//recursively printing out the nodes
public static String toString(Node r){
if(r==null)
return "";
else
return toString(r.left) + " " +r.value + " " +toString(r.right);
}
回答by pkm
public class TreeNode {
int val;
TreeNode left;
TreeNode right;
TreeNode(int x) {
val = x;
}
// Helper
public String toString() {
return "<" + toString(this) + ">";
}
// recursively printing out the nodes
public static String toString(TreeNode r) {
if (r == null)
return "";
else
return r.val + " " + toString(r.left) + " " + toString(r.right);
}
}
