使用 Python 中 Pygame 的二分搜索法可视化
原文:https://www . geesforgeks . org/binary-search-visualization-use-pygame-in-python/
像二分搜索法这样的算法通过可视化很容易理解。本文实现了一个可视化二分搜索法算法的程序。图形用户界面使用 pygame 库在 Python 中实现。
方法
生成随机数组，使用任何排序算法对其进行排序，并用条填充 pygame 窗口。条形是垂直的直线，代表数组元素。
- 将所有条形设置为绿色。
- 使用 pygame.time.delay()来降低算法的速度，这样我们就可以看到搜索过程。
- 实现一个计时器，看看算法如何执行。
- 这些操作是使用“pygame.event.get()”方法执行的，该方法存储用户执行的所有事件，如启动、重置。
- 蓝色用于高亮显示与找到的键相等的条。
- 橙色突出显示左右条。
下面是上述可视化工具的实现:
计算机编程语言
# Python implementation of the
# Sorting visualiser: Insertion Sort
# Imports
import pygame
import random
import time
pygame.font.init()
startTime = time.time()
# Total window
screen = pygame.display.set_mode(
(900, 650)
)
# Title and Icon
pygame.display.set_caption(
"BINARY SEARCH VISUALISER"
)
# Uncomment below lines for setting
# up the icon for the visuliser
# img = pygame.image.load('sorticon.png')
# pygame.display.set_icon(img)
# Boolean variable to run
# the program in while loop
run = True
# Window size and some initials
width = 900
length = 600
array = [0]*151
key = 0
foundkey = False
arr_clr = [(0, 204, 102)]*151
clr_ind = 0
clr = [(0, 204, 102), (255, 0, 0),
(0, 0, 153), (255, 102, 0)]
bigfont = pygame.font.SysFont("comicsans", 70)
fnt = pygame.font.SysFont("comicsans", 30)
fnt1 = pygame.font.SysFont("comicsans", 20)
# Sorting Algorithm: Heap Sort
def heapSort(array):
n = len(array)
for i in range(n//2-1, -1, -1):
heapify(array, i, n)
for i in range(n-1, 0, -1):
array[i], array[0] = array[0], array[i]
heapify(array, 0, i)
def heapify(array, root, size):
left = root*2+1
right = root*2+2
largest = root
if left < size and array[left] > array[largest]:
largest = left
if right < size and array[right] > array[largest]:
largest = right
if largest != root:
array[largest], array[root] = array[root], array[largest]
heapify(array, largest, size)
# Function to generate new Array
def generate_arr():
for i in range(1, 151):
arr_clr[i] = clr[0]
array[i] = random.randrange(1, 100)
heapSort(array)
# Initially generate a array
generate_arr()
# Function to refill the
# updates on the window
def refill():
screen.fill((255, 255, 255))
draw()
pygame.display.update()
pygame.time.delay(200)
def binarySearch(array, key):
left = 0
right = len(array)-1
while left < right:
arr_clr[left] = clr[1]
arr_clr[right] = clr[1]
refill()
refill()
mid = left+(right-left)//2
if array[mid] == key:
arr_clr[left] = clr[0]
arr_clr[right] = clr[0]
arr_clr[mid] = clr[2]
return 1
elif array[mid] < key:
arr_clr[left] = clr[0]
left = mid+1
else:
arr_clr[right] = clr[0]
right = mid-1
refill()
arr_clr[left] = clr[0]
arr_clr[right] = clr[0]
refill()
return -1
# Function to Draw the array values
def draw():
# Text should be rendered
txt = fnt.render("SEARCH: PRESS 'ENTER'",
1, (0, 0, 0))
# Position where text is placed
screen.blit(txt, (20, 20))
txt1 = fnt.render("NEW ARRAY: PRESS 'R'",
1, (0, 0, 0))
screen.blit(txt1, (20, 40))
txt2 = fnt1.render("ENTER NUMBER TO SEARCH:" +
str(key), 1, (0, 0, 0))
screen.blit(txt2, (600, 60))
text3 = fnt1.render("Running Time(sec): " +
str(int(time.time() - startTime)),
1, (0, 0, 0))
screen.blit(text3, (600, 20))
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)
# 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)
if foundkey == 1:
text4 = bigfont.render("Key Found. Press N to Reset Key", 1, (0, 0, 0))
screen.blit(text4, (100, 300))
elif foundkey == -1:
text4 = bigfont.render(
"Key Not Found. Press N to Reset Key", 1, (0, 0, 0))
screen.blit(text4, (30, 300))
# Program should be run
# continuously 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:
key = 0
foundkey = 0
generate_arr()
if event.key == pygame.K_n:
foundkey = 0
key = 0
for i in range(0, len(array)):
arr_clr[i] = clr[0]
if event.key == pygame.K_RETURN and key != 0:
foundkey = binarySearch(array, key)
if event.key == pygame.K_0:
key = key*10
if event.key == pygame.K_1:
key = key*10+1
if event.key == pygame.K_2:
key = key*10+2
if event.key == pygame.K_3:
key = key*10+3
if event.key == pygame.K_4:
key = key*10+4
if event.key == pygame.K_5:
key = key*10+5
if event.key == pygame.K_6:
key = key*10+6
if event.key == pygame.K_7:
key = key*10+7
if event.key == pygame.K_8:
key = key*10+8
if event.key == pygame.K_9:
key = key*10+9
draw()
pygame.display.update()
pygame.quit()
输出:
[https://media.geeksforgeeks.org/wp-content/cdn-uploads/20200727160706/binary-search-visualization.webm](https://media.geeksforgeeks.org/wp-content/cdn-uploads/20200727160706/binary-search-visualization.webm)版权属于：月萌API www.moonapi.com，转载请注明出处
