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docs: update the whole repository

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* fix some bugs
* delete duplicate files
* format code
This commit is contained in:
yanglbme
2019-05-09 19:32:54 +08:00
parent 163db8521a
commit 29948363da
368 changed files with 4372 additions and 30841 deletions
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59
DataStructures/Trees/ValidBSTOrNot.java
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@ -1,38 +1,37 @@
class Node
{
int data;
Node left, right;
public Node(int item)
{
data = item;
left = right = null;
package DataStructures.Trees;
public class ValidBSTOrNot {
class Node {
int data;
Node left, right;
public Node(int item) {
data = item;
left = right = null;
}
}
}
public class ValidBSTOrNot
{
//Root of the Binary Tree
Node root;
/* can give min and max value according to your code or
can write a function to find min and max value of tree. */
/* returns true if given search tree is binary
search tree (efficient version) */
boolean isBST() {
boolean isBST() {
return isBSTUtil(root, Integer.MIN_VALUE,
Integer.MAX_VALUE);
Integer.MAX_VALUE);
}
/* Returns true if the given tree is a BST and its
values are >= min and <= max. */
boolean isBSTUtil(Node node, int min, int max)
{
boolean isBSTUtil(Node node, int min, int max) {
/* an empty tree is BST */
if (node == null)
return true;
/* false if this node violates the min/max constraints */
if (node.data < min || node.data > max)
return false;
@ -40,23 +39,7 @@ public class ValidBSTOrNot
/* otherwise check the subtrees recursively
tightening the min/max constraints */
// Allow only distinct values
return (isBSTUtil(node.left, min, node.data-1) &&
isBSTUtil(node.right, node.data+1, max));
}
/* Driver program to test above functions */
public static void main(String args[])
{
ValidBSTOrNot tree = new ValidBSTOrNot();
tree.root = new Node(4);
tree.root.left = new Node(2);
tree.root.right = new Node(5);
tree.root.left.left = new Node(1);
tree.root.left.right = new Node(3);
if (tree.isBST())
System.out.println("IS BST");
else
System.out.println("Not a BST");
return (isBSTUtil(node.left, min, node.data - 1) &&
isBSTUtil(node.right, node.data + 1, max));
}
}