blasanka/data-structures

You will find this repo useful for to understand how basic Data Structures and Algorithms can be implemented using Java. Note: this is not containing Java generics features and Java 8, 9, 10 features because main purpose is not to focus in specific language(anyone can use same logic to other languages only the syntax differ)

Data Structures using Java

Note:

This repository updates everyday, check for updates and suggest anything.

How to run:

Download or clone the repository import to your favorite IDE and open any Main classes, then, you can run and check.

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Content:

1. Stack

• Provide Last In First Out(LIFO)
• Lastly added value will remove first.
• Example: When you press few keys on keyboard they are adding to a stack and when you press delete key lastly added value will remove first.

2. Queue (Linear Queue and Circular Queue)

• Provide First In First Out(FIFO)
• Firstly added value will remove first.
• Example: This is like a persons in a queue to get meds or something in real life, firstly came person will get meds first.

2. LinkedList

• Linked objects. Just like a simple class and properties/variables with a special property called --next to hold another Link/object memory address(In Java actually we don't have memory address rather we have hash code(example: #342ff3) for every object to uniquely identify that object.).
• [more info coming soon.]

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How to Contribute:

Star the repo then Fork it and add/change and pull request. Then, I will review and merge it. send a mail to [email protected]

data-structures's Issues

insertion sort

a = [3, 7, 4, 1, 8]

for index in range(1,len(a)):
    current = a[index]
    i = index

    while i>0 and a[i-1] > current:
        a[i] = a[i-1]
        i = i -1

    a[i] = current



print(a)

#lab session-------------------

A = []

for v in range(10):
    A.append(input('Enter a number: '))

print('\nunsorted array')
print A

def insertionSort(A):
    for j in range(1, len(A)):
        key = A[j]
        i = j - 1

        while(i >= 0 and A[i] > key):
            A[i+1] = A[i]
            i = i-1
        A[i+1] = key

insertionSort(A)

print('\nsorted array')
print(A)

print('\nsorted array elemenet by element')
for i in range(len(A)):
    print(A[i])

selection sort

def selectionSort(A):
    for j in range(len(A)):
        min = j
        for i in range(j+1,len(A)):
            if A[min] > A[i]:
                min = i
        temp = A[j]
        A[j] = A[min]
        A[min] = temp


arr = [1, -9, 3, 7]
selectionSort(arr)
print(arr)

quicksort

def partition(A, low, high):
    pivot = A[high]
    i = low -1
    for j in range(low, high):
        if A[j] <= pivot:
            i = i + 1
            A[i], A[j] = A[j], A[i]
    A[i + 1], A[high] = A[high], arr[i + 1]
    return i + 1


def quickSort(A, low, high):
    if low < high:
        q = partition(A, low, high)
        quickSort(A, low, q-1)
        quickSort(A, q+1, high)

arr = [20,51,11,1]
quickSort(arr, 0, len(arr)-1)
print(arr)