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# 11.47 (Tkinter: largest block) Write a program that displays a 10 *10 square matrix, as
# shown in Figure 11.17b. Each element in the matrix is a 0 or 1, randomly generated
# with a click of the Refresh button. Display each number centered in a text box.
# Allow the user to change the entry value. Click the Find Largest Block button to find
# a largest square submatrix that consists of 1s. Highlight the numbers in the block, as
# shown in Figure 11.17c.
import random
from tkinter import *
class GUI:
def __init__(self):
window = Tk()
self.frame = Frame(window)
self.frame.pack()
self.lst = []
for i in range(10):
x = []
for j in range(10):
x.append(Text(self.frame, width=2, height=1))
x[j].tag_configure("center", justify='center')
x[j].insert('1.0', str(random.randint(0, 1)))
x[j].tag_add("center", "1.0", "end")
x[j].grid(row=i, column=j)
self.lst.append(x)
btn = Button(window, text='Refresh', command=self.refresh)
btn2 = Button(window, text='Find largest block', command=self.find)
btn2.pack()
btn.pack()
window.mainloop()
def refresh(self):
for i in range(len(self.lst)):
for j in range(len(self.lst[1])):
self.lst[i][j].delete('1.0', END)
self.lst[i][j].tag_configure("center", justify='center')
self.lst[i][j].insert('1.0', str(random.randint(0, 1)))
self.lst[i][j].tag_add("center", "1.0", "end")
def find(self):
values = []
for i in range(10):
x = []
for j in range(10):
x.append(int(self.lst[i][j].get("1.0", END)))
values.append(x)
# Construct a sum matrix S[R][C] for the given M[R][C].
w = len(values)
h = len(values[1])
sum = [[0 for x in range(w)] for y in range(h)]
# Copy first row and first columns as it is from M[][] to S[][]
sum[0] = values[0]
for i in range(len(values)):
sum[i][0] = values[i][0]
# For other entries, use following expressions to construct S[][]
for i in range(1, w):
for j in range(1, h):
if values[i][j] == 1:
sum[i][j] = min(sum[i][j - 1], sum[i - 1][j],
sum[i - 1][j - 1]) + 1
# Find the maximum entry in S[R][C]
maxIndx = []
max = -1
for i in range(len(values)):
for j in range(len(values[0])):
if sum[i][j] > max:
maxIndx = []
maxIndx.append(i)
maxIndx.append(j)
max = sum[i][j]
elif sum[i][j] == max:
maxIndx.append(i)
maxIndx.append(j)
# select an entry
x = maxIndx[0]
y = maxIndx[1]
for i in range(x, x - max, -1):
for j in range(y, y - max, -1):
val = self.lst[i][j].get("1.0", END)
self.lst[i][j] = Text(self.frame, width=2, height=1, bg='gray')
self.lst[i][j].tag_configure("center", justify='center')
self.lst[i][j].insert(INSERT, val)
self.lst[i][j].tag_add("center", "1.0", "end")
self.lst[i][j].grid(row=i, column=j)
sum = [[str(x) for x in l] for l in sum]
print('\n'.join(map(', '.join, sum)))
print(maxIndx)
GUI()
