From 73e657a64a0af4c956226d712531c658e095bd4c Mon Sep 17 00:00:00 2001
From: HenryTech12 <henrycrownny@gmail.com>
Date: Sun, 27 Apr 2025 08:02:29 +0100
Subject: [PATCH] dynamic programming with java

---
 .../linkedlist/LinkedList.java                |  68 ++++++++
 .../linkedlist/Node.java                      |   7 +
 .../queue/MyQueue.java                        | 106 +++++++++++++
 .../search/MySearch.java                      |  34 ++++
 .../sort/MySort.java                          |  46 ++++++
 .../sort/SortType.java                        |   8 +
 .../stack/MyStack.java                        | 145 ++++++++++++++++++
 7 files changed, 414 insertions(+)
 create mode 100644 Java Collections Dynamic Programming/linkedlist/LinkedList.java
 create mode 100644 Java Collections Dynamic Programming/linkedlist/Node.java
 create mode 100644 Java Collections Dynamic Programming/queue/MyQueue.java
 create mode 100644 Java Collections Dynamic Programming/search/MySearch.java
 create mode 100644 Java Collections Dynamic Programming/sort/MySort.java
 create mode 100644 Java Collections Dynamic Programming/sort/SortType.java
 create mode 100644 Java Collections Dynamic Programming/stack/MyStack.java

diff --git a/Java Collections Dynamic Programming/linkedlist/LinkedList.java b/Java Collections Dynamic Programming/linkedlist/LinkedList.java
new file mode 100644
index 0000000..6cd900d
--- /dev/null
+++ b/Java Collections Dynamic Programming/linkedlist/LinkedList.java	
@@ -0,0 +1,68 @@
+package linkedlist;
+
+public class LinkedList
+{
+	Node head;
+	public void add(int data) {
+		Node node = new Node();
+		node.data = data;
+		
+		if(head == null) {
+			head = node;
+		}
+		else {
+			Node n = head;
+			while(n.next != null) {
+				n = n.next;
+			}
+			n.next = node;
+		}
+	}
+	
+
+	public int get(int index) {
+		Node n = head;
+		for(int i = 0; i < index; i++) {
+			n = n.next;
+		}
+		return n.data;
+	}
+	
+	public int getFirst() {
+		return head.data;
+	}
+	
+	public int getLast() {
+		return get(size() - 1);
+	}
+	
+	public int size() {
+		Node n = head;
+		int size = 0;
+		if(head != null) {
+		while(n.next != null) {
+			size++;
+			n = n.next;
+		}
+		size++;
+		}
+		return size;
+	}
+	
+	public boolean isEmpty() {
+		return size() == 0;
+	}
+	
+	public void clear() {
+		head = null;
+	}
+	
+	public void show() {
+		Node n = head;
+		while(n.next != null) {
+			System.out.println(n.data);
+			n = n.next;
+		}
+		System.out.println(n.data);
+	}
+}
diff --git a/Java Collections Dynamic Programming/linkedlist/Node.java b/Java Collections Dynamic Programming/linkedlist/Node.java
new file mode 100644
index 0000000..6628190
--- /dev/null
+++ b/Java Collections Dynamic Programming/linkedlist/Node.java	
@@ -0,0 +1,7 @@
+package linkedlist;
+
+public class Node
+{
+	int data;
+	Node next;
+}
diff --git a/Java Collections Dynamic Programming/queue/MyQueue.java b/Java Collections Dynamic Programming/queue/MyQueue.java
new file mode 100644
index 0000000..a4bfbea
--- /dev/null
+++ b/Java Collections Dynamic Programming/queue/MyQueue.java	
@@ -0,0 +1,106 @@
+package queue;
+
+public class MyQueue
+{
+	private int[] arr;
+	private int size = 0;
+	
+	public void enqueue(int data) {
+		expand();
+		arr[size-1] = data;
+	}
+	
+	private void expand() {
+		int tempSize = size + 1;
+		int temp[] = new int[tempSize];
+		for(int i = 0; i < size; i++) {
+			temp[i] = arr[i];
+		}
+		arr = temp;
+		size = tempSize;
+	}
+	
+	public int dequeue() {
+		int skip = 1;
+		int tempSize = size-1;
+		int temp[] = new int[tempSize];
+		for(int i = 0; i < size-1; i++) {
+			temp[i] = arr[skip+i];
+		}
+		int removedValue = arr[skip-1];
+		arr = temp;
+		size = tempSize;
+		return removedValue;
+	}
+	
+	public int peek() {
+		return arr[0];
+	}
+	
+	public int peekAt(int index) {
+		return arr[index];
+	}
+	
+	public void clear() {
+		arr = new int[0];
+		size = 0;
+	}
+	
+	public boolean contains(int data) {
+		for(int i = 0; i < size; i++) {
+			if(arr[i] == data) {
+				return true;
+			}
+			break;
+		}
+		return false;
+	}
+	
+	public int dequeueAt(int index) {
+		int tempSize = size-1;
+		int temp[] = new int[tempSize];
+		int removedValue = arr[size-1];
+		boolean isZero = false;
+		isZero = (index == 0);
+		for(int i = 0; i < size-1; i++) {
+			if(i != index) {
+				if(!isZero) {
+					temp[i] = arr[i];
+				}
+				else {
+					temp[i] = arr[i+1];
+				}
+			}
+			else {
+				temp[i] = arr[i+1];
+				removedValue = arr[i];
+			}
+		}
+		arr = temp;
+		size = tempSize;
+		return removedValue;
+	}
+	
+	public int[] copy(int[] data) {
+		int temp[] = new int[data.length];
+		for(int i = 0; i < data.length; i++) {
+			temp[i] = data[i];
+		}
+		return temp;
+	}
+	
+	public boolean isEmpty() {
+		return size == 0;
+	}
+	
+	public int size() {
+		return size;
+	}
+	
+	
+	public void show() {
+		for(int i = 0; i < size; i++) {
+			System.out.println(arr[i]);
+		}
+	}
+}
diff --git a/Java Collections Dynamic Programming/search/MySearch.java b/Java Collections Dynamic Programming/search/MySearch.java
new file mode 100644
index 0000000..71f8308
--- /dev/null
+++ b/Java Collections Dynamic Programming/search/MySearch.java	
@@ -0,0 +1,34 @@
+package search;
+import sort.*;
+
+public class MySearch
+{
+	public int linearSearch(int[] data, int target) {
+		 for(int i = 0; i < data.length; i++) {
+			 if(data[i] == target) {
+				 return i;
+			 }
+		 }
+		 return -1;
+	}
+	
+	//always pass in a sorted array
+	public int binarySearch(int[] arr, int target) {
+		int left = 0;
+		int right = arr.length - 1;
+	   
+		while(left <= right) {
+			int mid = (left + right) / 2;
+			if(arr[mid] == target) {
+				return mid;
+			}
+			else if(arr[mid] < target) {
+				left = mid + 1;
+			}
+			else {
+				right = mid - 1;
+			}
+		}
+		return -1;
+	}
+}
diff --git a/Java Collections Dynamic Programming/sort/MySort.java b/Java Collections Dynamic Programming/sort/MySort.java
new file mode 100644
index 0000000..7d53fe9
--- /dev/null
+++ b/Java Collections Dynamic Programming/sort/MySort.java	
@@ -0,0 +1,46 @@
+package sort;
+
+public class MySort
+{
+	private SortType type = SortType.ASC;
+	
+	
+	public int[] bubbleSort(int[] data, SortType mytype) {
+		for(int i = 0; i < data.length; i++) {
+			for(int j = 0; j < data.length - i - 1; j++) {
+				if(data[j] > data[j+1]) {
+					if(type.toString().equals(mytype.toString()))
+					  swap(data, j, j+1);
+			   }
+			   else {
+				  if(!type.toString().equals(mytype.toString()))
+				    swap(data,j,j+1);
+			   }
+			}
+		}
+		
+		return data;
+	}
+	
+	public void swap(int[] data, int index1, int index2) {
+		int temp = data[index1];
+		data[index1] = data[index2];
+		data[index2] = temp;
+	}
+	
+	public int[] selectionSort(int[] data) {
+	  for(int i = 0; i < data.length; i++) {
+		  int minIndex = i;
+			for(int j = i+1; j < data.length; j++) {
+				if(data[j] < data[minIndex]) {
+				    minIndex = j;
+				 }
+			} 
+			int temp = data[i];
+	        data[i] = data[minIndex];
+		    data[minIndex] = temp;
+		}
+		return data;
+	}
+
+}
diff --git a/Java Collections Dynamic Programming/sort/SortType.java b/Java Collections Dynamic Programming/sort/SortType.java
new file mode 100644
index 0000000..a3ae2c7
--- /dev/null
+++ b/Java Collections Dynamic Programming/sort/SortType.java	
@@ -0,0 +1,8 @@
+package sort;
+
+public enum SortType
+{
+	ASC, 
+	DESC
+}
+
diff --git a/Java Collections Dynamic Programming/stack/MyStack.java b/Java Collections Dynamic Programming/stack/MyStack.java
new file mode 100644
index 0000000..53f50be
--- /dev/null
+++ b/Java Collections Dynamic Programming/stack/MyStack.java	
@@ -0,0 +1,145 @@
+package stack;
+
+public class MyStack
+{
+	private int[] arr;
+	private int size = 0;
+	
+	public void push(int data) {
+		expand();
+	
+		int temp[] = new int[size];
+		for(int i = 0; i < size-1; i++) {
+			temp[i+1] = arr[i];
+		}
+		arr = temp;
+		arr[0] = data;
+	}
+	
+	public boolean isEmpty() {
+		return size == 0;
+	}
+	
+	public int size() {
+		return size;
+	}
+	
+	public int peek() {
+		return arr[0];
+	}
+	
+	public int pop() {
+		int skip = 1;
+		int tempSize = size-1;
+		int temp[] = new int[tempSize];
+		for(int i = 0; i < size-1; i++) {
+			temp[i] = arr[skip+i];
+		}
+		int removedValue = arr[skip-1];
+		arr = temp;
+		size = tempSize;
+		return removedValue;
+	}
+	
+	
+	private void expand() {
+	  int tempSize = size +1;
+	  int temp[] = new int[tempSize];
+	  for(int i = 0; i < size; i++) {
+		  temp[i] = arr[i];
+	  }
+	  arr = temp;
+	  size = tempSize;
+	}
+	
+	public boolean contains(int data) {	
+		return (binarySearch(data) != -1);
+	}
+	
+	public int[] sort() {
+		int temp[] = arr;
+		for(int i = 0; i < size; i++) {
+			for(int j = 0; j < size - 1; j++) {
+				if(arr[j] > arr[j+1]) {
+					int max = arr[j];
+					arr[j] = arr[j+1];
+					arr[j+1] = max;
+				}
+			}
+		}
+		return temp;
+	}
+	
+	public int[] copy(int[] data) {
+	  int temp[] = new int[data.length];
+	  for(int i = 0; i < data.length; i++) {
+		  temp[i] = arr[i];
+	  }
+	  return temp;
+	}
+	
+	private int binarySearch(int target) {
+		int left = 0;
+		int right = arr.length - 1;
+		int unsorted[] = copy(arr);
+		
+		sort();
+		while(left <= right) {
+			int mid = (left + right) / 2;
+			if(arr[mid] == target) {
+				arr = unsorted;
+				return mid;
+			}
+			else if(arr[mid] < target) {
+				left = mid + 1;
+			}
+			else {
+				right = mid - 1;
+			}
+		}
+		arr = unsorted;
+		return -1;
+	}
+	
+	public int popAt(int index) {
+		int tempSize = size-1;
+		int temp[] = new int[tempSize];
+		int removedValue = arr[size-1];
+		boolean isZero = false;
+		isZero = (index == 0);
+		
+		for(int i = 0; i < size-1; i++) {
+			if(i != index) {
+				if(!isZero) {
+			     temp[i] = arr[i];
+			   }
+			   else {
+				 temp[i] = arr[i+1];
+			   }
+			}
+			else {
+			   removedValue = arr[i];
+			   temp[i] = arr[i+1];		   
+			}
+		}
+		arr = temp;
+		size = tempSize;
+		return removedValue;
+	}
+	
+	public void clear() {
+		arr = new int[0];
+		size = 0;
+	}
+	
+	public int peekAt(int index) {
+		return arr[index];
+	}
+	
+	public void show() {
+		for(int i = 0; i < size; i++) {
+			System.out.println(arr[i]);
+		}
+	}
+	
+}