/*
 * Click nbfs://nbhost/SystemFileSystem/Templates/Licenses/license-default.txt to change this license
 */
package edu.slcc.asdv.caleb.recursiondemo;

/**
 *
 * @author caleb
 */
public class RecursionDemo {

    static void printNTimes(int nTimes, String message) {
        for (int i = 0; i < nTimes; ++i) {
            System.out.println(message);
        }
    }

    public static boolean isPalendrome(String s) {
        String backwards = "";
        for (int i = s.length() - 1; i >= 0; i--) {
            backwards += s.charAt(i);
        }
        return s.equals(backwards);
    }

    public static long fib(int n) {
        if (n == 1 || n == 2) {
            return 1;
        }
        System.out.println(n);
        return fib(n - 1) + fib(n - 2);
    }

    static void printNTimesRecursion(int nTimes, String message) {
        if (nTimes == 0) {
            return;
        }
        System.out.println(message);
        printNTimesRecursion(--nTimes, message);
    }

    public static boolean isPalendromeRecursion(String s) {
        if (s.length() == 0 || s.length() == 1) {
            return true;
        } else if (s.charAt(0) != s.charAt(s.length() - 1)) {
            return false;
        }
        return isPalendromeRecursion(s.substring(1, s.length() - 1));
    }

    public static long factorial(int n) {
        long fact;
        if (n == 1) {
            return 1;
        }
        fact = n * factorial(n - 1);
        return fact;
    }

    public static void printArrayRecursively(int[] arr, int index) {
        if (index == arr.length) {
            return;
        } else {
            System.out.print(arr[index] + " ");
            printArrayRecursively(arr, index + 1);
        }
    }

    /**
     *
     * @param arr the array to be searched
     * @param index the index of the array to manipulate
     * @param currentMax the current maximum of the array
     * @return the maximum of the array
     */
    public static int findMaximumRecursive(int arr[], int index, int currentMax) throws Exception {
        //System.out.println("at index " + index);
        if (index >= (arr.length)) {
            //throw new ArrayIndexOutOfBoundsException();
            return currentMax;
        }
        if (arr[index] >= currentMax) {
            currentMax = arr[index];
        }
        currentMax = findMaximumRecursive(arr, (index + 1), currentMax);
        return currentMax;
    }

    public static int findMaximumRecursive(int arr[]) throws Exception {
        // This method simply makes it possible to call findMaximumRecursive() without giving it currentMax or an index
        return findMaximumRecursive(arr, 0, Integer.MIN_VALUE);
    }

    public static void main(String[] args) throws Exception {
        //System.out.println(factorial(20));
        //printNTimesRecursion(1, "Hello Recursion");
        //System.out.println(fib(10));
        //System.out.println(isPalendrome("detartrated"));
        //System.out.println(isPalendromeRecursion("detartrated"));
        //int[] arr = {2, 3, 5, 6, 7, 8, 10, 32, 64, 128};
        //printArrayRecursively(arr, 0);
        System.out.println(findMaximumRecursive(new int[]{99, 1, 44, 2, 3, 55}));
        System.out.println(findMaximumRecursive(new int[]{1, 44, 2, 3}));
        System.out.println(findMaximumRecursive(new int[]{1, 44, 2, 3, 300}));
    }
}