2

我正在使用 tkinter 使用不同条形的高度来可视化不同的排序算法。我已经能够洗牌并在一些帮助后对它们进行排序。我现在遇到的问题是减慢条形的排序速度，因此可以看到每种算法的工作原理。这是我到目前为止所拥有的：

import tkinter as tk
import random

def swap_two_pos(pos_0, pos_1):
    Bar1x1, _, Bar1x2, _ = canvas.coords(pos_0)
    Bar2x1, _, Bar2x2, _ = canvas.coords(pos_1)
    canvas.move(pos_0, Bar2x1-Bar1x1, 0)
    canvas.move(pos_1, Bar1x2-Bar2x2, 0)


def insertion_sort():
    global barList
    global lengthList

    for i in range(len(lengthList)):
        cursor = lengthList[i]
        cursorBar = barList[i]
        pos = i

        while pos > 0 and lengthList[pos - 1] > cursor:
            lengthList[pos] = lengthList[pos - 1]
            barList[pos], barList[pos - 1] = barList[pos - 1], barList[pos]
            canvas.after(1000,swap_two_pos(barList[pos],barList[pos-1]))
            pos -= 1

        lengthList[pos] = cursor
        barList[pos] = cursorBar
        swap_two_pos(barList[pos],cursorBar)

def shuffle():
    global barList
    global lengthList
    canvas.delete('all')
    xstart = 5
    xend = 15
    barList = []
    lengthList = []

    for x in range(1,60):
        randomY = random.randint(1,390)
        x = canvas.create_rectangle(xstart,randomY,xend,395, fill='red')
        barList.append(x)
        xstart += 10
        xend += 10

    for bar in barList:
        x = canvas.coords(bar)
        length = x[3]-x[1]
        lengthList.append(length)

    for i in range(len(lengthList)-1):
        if lengthList[i] == min(lengthList):
            canvas.itemconfig(barList[i], fill='blue')
        elif lengthList[i] == max(lengthList):
            canvas.itemconfig(barList[i], fill='green')

window = tk.Tk()
window.title('Sorting')
window.geometry('600x435')
canvas = tk.Canvas(window, width='600', height='400')
canvas.grid(column=0,row=0, columnspan = 50)

insert = tk.Button(window, text='Insertion Sort', command=insertion_sort)
shuf = tk.Button(window, text='Shuffle', command=shuffle)
insert.grid(column=1,row=1)
shuf.grid(column=0, row=1)

shuffle()
window.mainloop()

如您所见，我尝试after()在插入排序函数中使用该方法，但它所做的只是冻结窗口并使其不响应。如果没有这种方法，它可以正常工作，只是不会以可见的速度进行。

4

2 回答 2

1

利用生成器函数（关键字yield），您可以暂停代码中间循环的执行，以花时间显示已更改的画布元素，更新计算等，然后在next重复调用生成器时恢复执行，直到排序完成。

我在代码中添加了一些注释，但最好的方法可能是盯着它看，直到你说服自己它按预期工作。这是您需要了解的模式，因为它对构建您想要构建的动画非常有用。

import tkinter as tk
import random


def swap_two_pos(pos_0, pos_1):
    Bar1x1, _, Bar1x2, _ = canvas.coords(pos_0)
    Bar2x1, _, Bar2x2, _ = canvas.coords(pos_1)
    canvas.move(pos_0, Bar2x1-Bar1x1, 0)
    canvas.move(pos_1, Bar1x2-Bar2x2, 0)


def _insertion_sort():
    global barList
    global lengthList

    for i in range(len(lengthList)):
        cursor = lengthList[i]
        cursorBar = barList[i]
        pos = i

        while pos > 0 and lengthList[pos - 1] > cursor:
            lengthList[pos] = lengthList[pos - 1]
            barList[pos], barList[pos - 1] = barList[pos - 1], barList[pos]
            swap_two_pos(barList[pos],barList[pos-1])   # <-- updates the display
            yield                                       # <-- suspends the execution
            pos -= 1                                    # <-- execution resumes here when next is called

        lengthList[pos] = cursor
        barList[pos] = cursorBar
        swap_two_pos(barList[pos],cursorBar)


worker = None    # <-- Not a thread in spite of the name.

def insertion_sort():     # <-- commands the start of both the animation, and the sort
    global worker
    worker = _insertion_sort()
    animate()


def animate():      # <-- commands resuming the sort once the display has been updated
                    # controls the pace of the animation
    global worker
    if worker is not None:
        try:
            next(worker)
            window.after(10, animate)    # <-- repeats until the sort is complete,
        except StopIteration:            # when the generator is exhausted
            worker = None
        finally:
            window.after_cancel(animate) # <-- stop the callbacks


def shuffle():
    global barList
    global lengthList
    canvas.delete('all')
    xstart = 5
    xend = 15
    barList = []
    lengthList = []

    for x in range(1, 60):
        randomY = random.randint(1, 390)
        x = canvas.create_rectangle(xstart, randomY, xend, 395, fill='red')
        barList.append(x)
        xstart += 10
        xend += 10

    for bar in barList:
        x = canvas.coords(bar)
        length = x[3] - x[1]
        lengthList.append(length)

    for i in range(len(lengthList)-1):
        if lengthList[i] == min(lengthList):
            canvas.itemconfig(barList[i], fill='blue')
        elif lengthList[i] == max(lengthList):
            canvas.itemconfig(barList[i], fill='green')


window = tk.Tk()
window.title('Sorting')
window.geometry('600x435')
canvas = tk.Canvas(window, width='600', height='400')
canvas.grid(column=0,row=0, columnspan = 50)

insert = tk.Button(window, text='Insertion Sort', command=insertion_sort)
shuf = tk.Button(window, text='Shuffle', command=shuffle)
insert.grid(column=1,row=1)
shuf.grid(column=0, row=1)

shuffle()
window.mainloop()
于 2019-04-19T08:22:20.637 回答
0

耗时的函数是“swap_two_pos()”，这是灾难性的，你在每个循环中运行它，你应该做的是完成排序然后重新绘制条形图，下面是你的代码修改后在没有 GUI 冻结的情况下工作，添加了一个函数并删除了“交换两个位置（）”函数。

import tkinter as tk
import random


def insertion_sort():
    global barList
    global lengthList

    for i in range(len(lengthList)):
        cursor = lengthList[i]
        cursorBar = barList[i]
        pos = i

        while pos > 0 and lengthList[pos - 1] > cursor:
            lengthList[pos] = lengthList[pos - 1]
            barList[pos], barList[pos - 1] = barList[pos - 1], barList[pos]
            # canvas.after(1000,swap_two_pos(barList[pos],barList[pos-1]))
            pos -= 1

        lengthList[pos] = cursor
        barList[pos] = cursorBar
    refresh()
        # swap_two_pos(barList[pos],cursorBar)

def refresh():
    canvas.delete('all')
    xstart = 5
    xend = 15

    for i, length in enumerate(lengthList): #range(1,60):
        y = random.randint(1,390)
        x = canvas.create_rectangle(xstart,length,xend,395, fill='red')
        barList.append(x)
        xstart += 10
        xend += 10


def shuffle():
    global barList
    global lengthList
    canvas.delete('all')
    xstart = 5
    xend = 15
    barList = []
    lengthList = []

    for x in range(1,60):
        randomY = random.randint(1,390)
        x = canvas.create_rectangle(xstart,randomY,xend,395, fill='red')
        barList.append(x)
        xstart += 10
        xend += 10

    for bar in barList:
        x = canvas.coords(bar)
        length = x[3]-x[1]
        lengthList.append(length)

    for i in range(len(lengthList)-1):
        if lengthList[i] == min(lengthList):
            canvas.itemconfig(barList[i], fill='blue')
        elif lengthList[i] == max(lengthList):
            canvas.itemconfig(barList[i], fill='green')

window = tk.Tk()
window.title('Sorting')
window.geometry('600x435')
canvas = tk.Canvas(window, width='600', height='400')
canvas.grid(column=0,row=0, columnspan = 50)

insert = tk.Button(window, text='Insertion Sort', command=insertion_sort)
shuf = tk.Button(window, text='Shuffle', command=shuffle)
insert.grid(column=1,row=1)
shuf.grid(column=0, row=1)

shuffle()
window.mainloop()
于 2019-04-19T02:54:18.667 回答