HDegano

    public class TreeNode {
        public int val;
        public TreeNode left;
        public TreeNode right;
        public TreeNode(int x) { val = x; }
    }
    
    public bool IsBalanced(TreeNode root) {
        if(root == null) return true;
        

HDegano

public class MinStack {
    
    private Stack<int> _stack = new Stack<int>();
    private Stack<int> _min = new Stack<int>();
    
    public void Push(int x) {
        _stack.Push(x);    
        
        if(_min.Count == 0) _min.Push(x);
        else {

HDegano

public static bool balanced_brackets(string S)
{
    var open = new List<char>(){'(', '{', '['};

    var stack = new Stack<char>();

    foreach (var i in S)
    {
        if (open.Contains(i)) stack.Push(i);
        

HDegano

/*
Assumes no duplicate
O(logN)
*/

public int FindElementInRotatedSortedArray(int[] ar, int k){
  
  int n = ar.Length;
  int lo = 0;
  int hi = n - 1;

HDegano

//Assumes there are no duplicate 
//O(log n)
public int FindMinRotatedArray(int[] ar){
  
  int n = ar.Length;
  int lo = 0;
  int hi = n - 1;
  while(lo <= hi){
    
    if(ar[lo] <= ar[hi]) // (sub) array is already sorted, yay!