def random(n, p):
a = stdarray.create2D(n, n, False)
for i in range(n):
for j in range(n):
a[i][j] = stdrandom.bernoulli(p)
return a
def flow(isOpen):
n = len(isOpen)
isFull = stdarray.create2D(n, n, False)
#以下为脚手架基础上，新增的部分
for j in range(n):
isFull[0][j] = isOpen[0][j]
for i in range(1, n):
for j in range(n):
if isOpen[i - 1][j] and isOpen[i][j]:
isFull[i][j] = True
return isFull
def generate_transition_matrix(weblist):
print('enter generate_transition_matrix()')
transition_matrix = stdarray.create2D(3, 3, 0)
wbnamelist = [weblist[i].url for i in range(len(weblist))]
print(wbnamelist)
for wb in weblist:
i = wbnamelist.index(wb.url)
for link in wb.link:
j = wbnamelist.index(link[0])
transition_matrix[i][j] = link[1]
print('return transition_matrix:', transition_matrix)
return transition_matrix
def lifegame(life):
'''
recursive return the adjacent part block
:param x:
:param y:
:return:
'''
stddraw.clear()
draw(life)
stddraw.show(500)
for line in life:
print(line)
life2 = stdarray.create2D(10, 10, 0)
for x in range(10):
for y in range(10):
print('x is {0},y is {1}'.format(x, y))
a = 0
for i in range(x - 1, x + 2):
# print('i is {0}'.format(i))
for j in range(y - 1, y + 2):
# print('j is {0}'.format(j))
if i < 0 or i > 9 or j < 0 or j > 9:
pass
else:
a += life[i][j]
print(
'i is {0},j is {1},life[{0}][{1}] is {3},a is{2}'.
format(i, j, a, life[i][j]))
if a == 0:
print(x, y, 'no alive in 9')
pass
else:
life2[x][y] = isalive(life, x, y)
lifegame(life2)
接受命令行参数 moves，从标准输入读取一个转换矩阵（浮点数），通过moves次向量-矩阵乘法计算，计算
一个随机冲浪者经过moves步跳转到达各页面的概率。
最后在标准输出中输出页面排名
命令行模式：
python3 tansition.py<tiny.txt|python3 markov.py 20
'''
from stdpackage import stdio,stdarray
import sys
moves = int(sys.argv[1])
n = stdio.readInt()
stdio.readInt()
p = stdarray.create2D(n,n,0.0)
for i in range(n):
for j in range(n):
p[i][j] = stdio.readFloat()
ranks = stdarray.create1D(n,0.0)
ranks[0] = 1.0
for i in range(moves):
new_ranks = stdarray.create1D(n,0.0)
for k in range(n):
for j in range(n):
new_ranks[j] += ranks[k]*p[k][j]
ranks = new_ranks
for i in range(n):
#计算输出转换矩阵，矩阵上第i行第j列的数字，代表从i页跳转到 j页的概率
from stdpackage import stdarray, stdio
n = stdio.readInt()
linkCounts = stdarray.create2D(n, n, 0)
outDegress = stdarray.create1D(n, 0)
while not stdio.isEmpty():
i = stdio.readInt()
j = stdio.readInt()
outDegress[i] += 1
linkCounts[i][j] += 1
stdio.writeln(str(n) + ' ' + str(n))
for i in range(n):
for j in range(n):
p = (0.8 * linkCounts[i][j] / outDegress[i]) + (0.2 / n)
stdio.writef('%8.5f', p)
stdio.writeln()
1.输入跳转总次数n
2. 从页面0开始
3. 随机生成概率 sp，根据sp跳转到下一个页面，对于被跳转到的页面计数
4。重复3，直到总次数耗尽
5。输出每个页面被跳转到的比例（次数／n)
'''
from stdpackage import stdio, stdarray, stddraw
import random
import sys
moves = int(sys.argv[1])
n = stdio.readInt()
stdio.readInt()
P = stdarray.create2D(n, n, 0.0)
P_accumulated = stdarray.create2D(n, n, 0.0)
SP = stdarray.create1D(n, 0.0)
for i in range(n):
for j in range(n):
P[i][j] = stdio.readFloat()
for i in range(n):
for j in range(n):
for h in range(j + 1):
P_accumulated[i][j] += P[i][h]
def find_page(i, p):
j = 0
while j < n:
def main(n):
life = stdarray.create2D(10, 10, 0)
stddraw.setXscale(-1, 10)
stddraw.setYscale(-1, 10)
life = initiate(life, n)
lifegame(life)