Sorting Algorithim.py

# Python implementation for visualizing merge sort.
import pygame
import random

pygame.font.init()
# window
screen = pygame.display.set_mode((900, 650))

# Title and Icon
pygame.display.set_caption("Sorting Algorithm Visualisation")

# Boolean variable to run the program in while loop
run = True

# Window size
width = 900
length = 600
array = [0] * 151
arr_clr = [(0, 255, 255)] * 151
clr_ind = 0
clr = [(0, 204, 204), (255, 0, 0),
       (0, 0, 153), (255, 102, 0)]
fnt = pygame.font.SysFont("comicsans", 30)
fnt1 = pygame.font.SysFont("comicsans", 20)


# Generate new Array
def generate_arr():
    for i in range(1, 151):
        arr_clr[i] = clr[0]
        array[i] = random.randrange(1, 100)


generate_arr()


def refill():
    screen.fill((255, 255, 255))
    draw()
    pygame.display.update()
    pygame.time.delay(20)


# Sorting Algo:Merge sort
def mergesort(array, l, r):
    mid = (l + r) // 2
    if l < r:
        mergesort(array, l, mid)
        mergesort(array, mid + 1, r)
        merge(array, l, mid,
              mid + 1, r)


def merge(array, x1, y1, x2, y2):
    i = x1
    j = x2
    temp = []
    pygame.event.pump()
    while i <= y1 and j <= y2:
        arr_clr[i] = clr[1]
        arr_clr[j] = clr[1]
        refill()
        arr_clr[i] = clr[0]
        arr_clr[j] = clr[0]
        if array[i] < array[j]:
            temp.append(array[i])
            i += 1
        else:
            temp.append(array[j])
            j += 1
    while i <= y1:
        arr_clr[i] = clr[1]
        refill()
        arr_clr[i] = clr[0]
        temp.append(array[i])
        i += 1
    while j <= y2:
        arr_clr[j] = clr[1]
        refill()
        arr_clr[j] = clr[0]
        temp.append(array[j])
        j += 1
    j = 0
    for i in range(x1, y2 + 1):
        pygame.event.pump()
        array[i] = temp[j]
        j += 1
        arr_clr[i] = clr[2]
        refill()
        if y2 - x1 == len(array) - 2:
            arr_clr[i] = clr[3]
        else:
            arr_clr[i] = clr[0]


# Draw the array values
def draw():
    # Text should be rendered
    txt = fnt.render("Press" \
                     " 'Enter' To Begin Sorting.", 1, (0, 0, 0))
    # Position where text is placed
    screen.blit(txt, (20, 20))
    txt1 = fnt.render("PRESS 'R' FOR NEW ARRAY.",
                      1, (0, 0, 0))
    screen.blit(txt1, (20, 50))
    txt2 = fnt1.render("TYPE: " \
                       "MERGE SORT", 1, (0, 0, 0))
    screen.blit(txt2, (600, 60))
    element_width = (width - 150) // 150
    boundry_arr = 900 / 150
    boundry_grp = 550 / 100
    pygame.draw.line(screen, (0, 0, 0),
                     (0, 95), (900, 95), 6)
    for i in range(1, 100):
        pygame.draw.line(screen,
                         (224, 224, 224),
                         (0, boundry_grp * i + 100),
                         (900, boundry_grp * i + 100), 1)

    # Drawing the array values as lines
    for i in range(1, 151):
        pygame.draw.line(screen, arr_clr[i], \
                         (boundry_arr * i - 3, 100), \
                         (boundry_arr * i - 3, array[i] * boundry_grp + 100), \
                         element_width)


# Infinite loop to keep the window open
while run:
    # background
    screen.fill((255, 255, 255))
    # Event handler stores all event
    for event in pygame.event.get():
        # If we click Close button in window
        if event.type == pygame.QUIT:
            run = False
        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_r:
                generate_arr()
            if event.key == pygame.K_RETURN:
                mergesort(array, 1, len(array) - 1)
    draw()
    pygame.display.update()

pygame.quit()