使用 PyQt5 的子集搜索可视化工具
在本文中，我们将看到如何制作一个 PyQt5 应用程序，它将可视化子集搜索算法。
子集搜索：有时我们会遇到检查一个列表是否只是列表的扩展，即是否只是一个列表的超集的问题。这类问题在竞争性编程中非常流行。
例子 -
Input: list = [1, 2, 3, 4, 5, 6, 7], sub-list = [2, 4, 7]
Output : List Found
Input: list = [1, 2, 3, 4, 5, 6, 7], sub-list = [5, 1, 7]
Output : List Found
GUI implementation steps :
1. Create a list of label according to the given list of numbers
2. Set their text, border, color and geometry with respective gap from each other
3. Each label height should be proportional to the value of each number
4. Create a start and pause push button to start the searching and pause the searching
5. Create a result label to show the searching status
Back end implementation steps :
1. Create label list corresponding to the given numbers
2. Create variable for the list index and sub-list index and flag for searching
3. Add action to the push button their action should change the flag status i.e start action should make flag true and pause action should make flag false and a counter to count number of matches
4. Create timer object which calls a method after every specific time
5. Inside the timer method check for the flag is flag is true begin the perfect sub-list search algorithm
6. Check for the first element of sub-list with first element of the list if found increment sub-list index, increment counter and reset the index of list else increment list index
7. If the index becomes equal to the list length stop the search and show result as not found.
8. If counter becomes equal to the length of the sub-list show result as found.
下面是实现
# 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]
# desired list
desired = [10, 11, 8, 4]
def __init__(self):
super().__init__()
# setting title
self.setWindowTitle("Sub Set 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
# list to hold labels
self.label_list = []
# match sub list
self.match = []
# index of both list
self.list_index = 0
self.sub_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 forth 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(320, 280, 250, 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(300)
# method called by timer
def showTime(self):
# checking if flag is true
if self.start:
# if index exceeds limit
if self.list_index >= len(self.number):
# stop the search and show result not found
self.start = False
self.result.setText("Not Found")
return
# check for the element
if self.desired[self.sub_index] == self.number[self.list_index]:
# append it the match counter
self.match.append(self.list_index)
# make label color yellow and rest of whitee color
for i in range(len(self.label_list)):
self.label_list[i].setStyleSheet(
"border : 1px solid yellow;"
"background-color : white;"
)
# dor matched label make them yellow color
if i in self.match:
self.label_list[i].setStyleSheet(
"border : 2px solid yellow;"
"background-color : yellow;" )
# increment sub index
self.sub_index += 1
# reset the list index
self.list_index = 0
# if not found
else:
# make checked index label grey
self.label_list[self.sub_index + self.list_index].setStyleSheet(
"border :" "1px solid black;"
"background-color : grey;" )
# increment list index
self.list_index += 1
# if matches become equal to desired list
if len(self.match) == len(self.desired):
# stop search
self.start =False
# show result
self.result.setText("Found at : " + str(self.match))
# make matched index green
for i in self.match:
self.label_list[i].setStyleSheet(
"border : 2px solid green;"
"background-color : lightgreen;")
# 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())
输出 ：