ravichandrae

public class IndexElementArray {
    public static void main(String[] args) {
        System.out.println(indexElement(new int[] {-5, -3, 0, 3, 5})); //Expect True
        System.out.println(indexElement(new int[] {-5, -3, 0, 1, 2})); //Expect false
        System.out.println(indexElement(new int[] {0, 2, 3, 4, 5})); //Expect True
        System.out.println(indexElement(new int[] {-1, 0, 1, 2, 4})); //Expect True
        System.out.println(indexElement(new int[] {-10, 10, 20, 30, 40})); //Expect false
    }

    private static boolean indexElement(int []arr) {

ravichandrae

public class Main {
    public static void main(String[] args) {
        System.out.println(maxElementInUnimodalArray(new int[]{1, 2, 5, 4, 3})); //Expected 5
        System.out.println(maxElementInUnimodalArray(new int[]{1, 2, 3, 4, 5})); //Expected 5
        System.out.println(maxElementInUnimodalArray(new int[]{5, 4, 3, 2, 1})); //Expected 5
        System.out.println(maxElementInUnimodalArray(new int[]{6})); //Expected 6
    }

    private static int maxElementInUnimodalArray(int[] arr) {
        if (arr == null || arr.length == 0) {

ravichandrae

import java.util.Stack;

public class ExpressionEvaluation {
    public static void main(String[] args) {
        String expression = "add( 1, 2)";
        int result = evaluateExpression(expression);
        System.out.println(result);
        expression = "add(sub(2, 1), 3)";
        System.out.println(evaluateExpression(expression));
        expression = "add(3, sub(22, 20))";

ravichandrae

import java.util.HashMap;
import java.util.Map;

public class RomanNumbers {

    public static void main(String[] args) {
        for (int i = 1; i <= 50; i++) {
            String roman = intToRoman(i);
            System.out.println(roman + " = " + romanToInt(roman));
        }

ravichandrae

public class RotatedSortedArray {
    public static void main(String[] args) {
        testFind();
    }

    public static void testFind() {
        System.out.println(find(null, 10));// Expect -1
        int[] arr1 = new int[]{};
        System.out.println(find(arr1, 100));// Expect -1
        int[] arr2 = new int[]{10};

ravichandrae

import java.util.HashSet;
import java.util.Map;
import java.util.Objects;
import java.util.Set;

public class PairsTest {
    static class IntPair {
        int x, y;
        public IntPair(int a, int b) {
            this.x = a;

ravichandrae

def permutations(lst):
    return permutations_util(lst, 0)


def permutations_util(lst, index):
    perms = []
    if index == len(lst) - 1:
        perms.append(lst.copy())
    for i in range(index, len(lst)):
        lst[i], lst[index] = lst[index], lst[i]

ravichandrae

import java.util.HashMap;
import java.util.Map;

public class LongestSubarrayUnique {
    public static void main(String[] args) {
        System.out.println(longestDistinctSubarray(null)); //Expected 0
        System.out.println(longestDistinctSubarray(new int[]{})); //Expected 0
        System.out.println(longestDistinctSubarray(new int[]{1})); //Expected 1
        System.out.println(longestDistinctSubarray(new int[]{1, 2, 3, 4, 5})); //Expected 5
        System.out.println(longestDistinctSubarray(new int[]{23, 9, 36, 23, 4})); //Expected 4

ravichandrae

def countBST(n):
    """
    :param n: a positive integer
    :return: Number of all possible binary search trees (BST) with n unique numbers
    The number is called a Catalan number F(n) = C(2*n, n) / (n+1) = (2*n)! / (n+1)! * n!
    As the above formula involves calculating factorial which is laborious and can overflow in some cases,
    We can use the following recurrence relation to make the calculation simple.
    F(0) = 1
    F(n+1) = (2*(2*n + 1) / (n+2)) * F(n)
    """

ravichandrae

import java.util.Arrays;

public class LongestIncreasingSubsequence {
    public static void main(String[] args) {
        System.out.println(longestIncreasingSubsequence(null)); //Expected 0
        System.out.println(longestIncreasingSubsequence(new int[]{})); //Expected 0
        System.out.println(longestIncreasingSubsequence(new int[]{1})); //Expected 1
        System.out.println(longestIncreasingSubsequence(new int[]{1, 5, 10})); //Expected 3
        System.out.println(longestIncreasingSubsequence(new int[]{1, 5, 2, 7, 6, 8})); //Expected 4
        System.out.println(longestIncreasingSubsequence(new int[]{6, 1, 7, 3, 9, 4, 11, 13})); //Expected 5