fanzhang312

def remove(text):
    for letter in text:
        if letter.lower() in ['a','e','i','o','u']:
            text = text.replace(letter, '')
    return text
    
    
import re

def anti_vowels(text):

fanzhang312

public static int[] topK(int[] arr, int k) {
	// default is ascending order
	Queue<Integer> queue = new PriorityQueue<Integer>();
	int i = 0;
	for (; i < k; i++) {
		queue.add(arr[i]);
	}
	for (; i < arr.length; i++) {
		queue.add(arr[i]);
		queue.poll(); // Retrieves and removes the head of this queue, which is smallest element in the queue

fanzhang312

// Find the minimum path sum (from root to leaf)
public static int minPathSum(TreeNode root) {
	if(root == null) return 0;
	int sum = root.val;
	
	int leftSum = minPathSum(root.left);
	int rightSum = minPathSum(root.right);
	
	if(leftSum < rightSum){
		sum += leftSum;

fanzhang312

public static boolean isFibo(long n){
  return isPerfectSquare(5*n*n+4) || isPerfectSquare(5*n*n-4);
}

public static boolean isPerfectSquare(double a){
  int s = (int) Math.sqrt(a);
  return s*s == a;
}

fanzhang312

public static boolean validBST(int[] arr){
    int lowerbound = Integer.MIN_VALUE;
    Stack<Integer> stack = new Stack<Integer>();
    
    for(int i : arr){
        if(i < lowerbound) return false;
        while(!stack.isEmpty() && i > stack.peek()){
            lowerbound = stack.pop();
        }
        stack.push(i);