极客教程PyQt5 – 跳跃搜索的可视化工具
在这篇文章中，我们将看到如何制作一个PyQt5应用程序，它可以将跳跃搜索算法可视化。和二进制搜索一样，跳转搜索是一种针对排序数组的搜索算法。其基本思想是通过固定步骤的跳转或跳过一些元素来检查更少的元素（比线性搜索），而不是搜索所有元素。
GUI实施步骤：
- 根据给定的数字列表创建一个标签列表
-
设置它们的文字、边框、颜色和几何形状，并使它们之间有各自的间隙
- 每个标签的高度应与每个数字的值成比例
- 创建一个开始和暂停的按钮来开始搜索和暂停搜索
- 创建一个结果标签以显示搜索状态
**算法实施步骤： **
- 创建对应于给定数字的标签列表。
- 为跳转索引和线性搜索的索引创建变量。同时，为线性搜索和跳转搜索过程建立一个计数器和标志。
- 为按钮添加动作，其动作应改变标志状态，即启动动作应使标志为真，暂停动作应使标志为假。
- 创建定时器对象，在每个特定时间后调用一个方法。
- 在定时器方法中，检查标志。如果标志为真，开始跳转搜索，检查跳转标志是否为真，开始跳转索引。
- 如果跳转指数值等于所需值，使标签变成绿色，并通过标签显示结果。如果索引值较大，则停止索引的跳转，并开始线性搜索。
- 通过线性搜索检查索引值，如果找到，通过标签显示，否则显示结果为未找到。
以下是实现方法
# importing libraries
from PyQt5.QtWidgets import *
from PyQt5 import QtCore, QtGui
from PyQt5.QtGui import *
from PyQt5.QtCore import *
import sys
class Window(QMainWindow):
# list of numbers
number = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15]
def __init__(self):
super().__init__()
# setting title
self.setWindowTitle("Jump search ")
# setting geometry
self.setGeometry(100, 100, 600, 400)
# calling method
self.UiComponents()
# showing all the widgets
self.show()
# method for widgets
def UiComponents(self):
# start flag
self.start = False
# linear search and binary search flag
self.linear = False
self.jump = True
# list to hold labels
self.label_list = []
# desired value
self.desired = 11
# step size
self.step = 4
# counter to calculate index
self.counter = 0
# index used to jumping
self.index = 0
# local index for linear search
self.linear_index = 0
# local counter
c = 0
# iterating list of numbers
for i in self.number:
# creating label for each number
label = QLabel(str(i), self)
# adding background color and border
label.setStyleSheet("border : 1px solid black; background : white;")
# aligning the text
label.setAlignment(Qt.AlignTop)
# setting geometry using local counter
# first parameter is distance from left and second is distance from top
# third is width and fourth is height
label.setGeometry(50 + c * 30, 50, 20, i * 10 + 10)
# adding label to the label list
self.label_list.append(label)
# incrementing local counter
c = c + 1
# creating push button to start the search
self.search_button = QPushButton("Start Search", self)
# setting geometry of the button
self.search_button.setGeometry(100, 270, 100, 30)
# adding action to the search button
self.search_button.clicked.connect(self.search_action)
# creating push button to pause the search
pause_button = QPushButton("Pause", self)
# setting geometry of the button
pause_button.setGeometry(100, 320, 100, 30)
# adding action to the search button
pause_button.clicked.connect(self.pause_action)
# creating label to show the result
self.result = QLabel("To search : " + str(self.desired), self)
# setting geometry
self.result.setGeometry(350, 280, 200, 40)
# setting style sheet
self.result.setStyleSheet("border : 3px solid black;")
# adding font
self.result.setFont(QFont('Times', 10))
# setting alignment
self.result.setAlignment(Qt.AlignCenter)
# creating a timer object
timer = QTimer(self)
# adding action to timer
timer.timeout.connect(self.showTime)
# update the timer every 300 millisecond
timer.start(500)
# method called by timer
def showTime(self):
# checking if flag is true
if self.start:
# implementing jump search
# implementing jumping gap
if self.jump:
# checking if jump index is greater then the length of list
if self.counter * self.step >= len(self.number):
# setting linear indes
self.linear_index = self.index - self.step
# setting counter value
self.counter = 0
# making jumping false
self.jump = False
# making linear flag true
self.linear = True
# updating the index
self.index = self.step * self.counter
# checking if desired value get found
if self.number[self.index] == self.desired:
# stopping the search
self.start = False
self.jump = False
# show result in the result label
self.result.setText("Found at index : " + str(self.index))
# making the label color green
self.label_list[self.index].setStyleSheet("border : 2px solid green;"
"background-color : lightgreen;")
# if not found
else:
# making the label color grey
self.label_list[self.index].setStyleSheet("border : 1px solid black;"
"background-color : grey;")
# if index value is greater
if self.number[self.index] > self.desired:
# setting linear index
self.linear_index = self.index - self.step
# updating the counter value
self.counter = 0
# making linear flag True
self.linear = True
# stopping the jumping
self.jump = False
# updating the counter
self.counter += 1
# updating the index
self.index = self.step * self.counter
# if index exceeds the limit
if self.counter * self.step >= len(self.number):
# updating the linear search
self.linear_index = self.index - self.step
# updating the counter value
self.counter = 0
# stopping the jumping
self.jump = False
# starting linear search
self.linear = True
# linear search
if self.linear:
# if counter become equal to steop
if self.counter == self.step:
# stop the search
self.start = False
# show result i.e not found
self.result.setText("Not found")
# if linear index is negative
if self.linear_index < 0:
# making it zero
self.linear_index = 0
# checking value if found
if self.number[self.counter + self.linear_index] == self.desired:
# stop the search
self.linear = False
self.start = False
# show result
self.result.setText("Found at index : " + str(self.counter +
self.linear_index))
# make label color green
self.label_list[self.counter + self.linear_index].setStyleSheet(
"border : 2px solid green;"
"background-color : lightgreen;")
# if not found
else:
# make label color grey
self.label_list[self.counter + self.linear_index].setStyleSheet(
"border : 1px solid black;"
" background-color : grey;")
# updating the counter
self.counter += 1
# method called by search button
def search_action(self):
# making flag true
self.start = True
# showing text in result label
self.result.setText("Started searching...")
# method called by pause button
def pause_action(self):
# making flag false
self.start = False
# showing text in result label
self.result.setText("Paused")
# create pyqt5 app
App = QApplication(sys.argv)
# create the instance of our Window
window = Window()
# start the app
sys.exit(App.exec())