Python 获取RPN树大小
我已经实现了下面的“tree sizer”,但它在某些情况下失败,下面的示例返回大小2,而它应该返回大小4,有人能帮我吗。我已经写了好几次了,但都没有用,它总是失败Python 获取RPN树大小,python,tree,genetic-algorithm,genetic-programming,rpn,Python,Tree,Genetic Algorithm,Genetic Programming,Rpn,我已经实现了下面的“tree sizer”,但它在某些情况下失败,下面的示例返回大小2,而它应该返回大小4,有人能帮我吗。我已经写了好几次了,但都没有用,它总是失败 def getRPNdepth(expression): treesize=0 maxtreesize=treesize mintreesize=treesize tmpexp=expression tmpfmla = [1 if n[0] == 'x' else n for n in tmp
def getRPNdepth(expression):
treesize=0
maxtreesize=treesize
mintreesize=treesize
tmpexp=expression
tmpfmla = [1 if n[0] == 'x' else n for n in tmpexp]
print(tmpfmla)
try:
stack = []
for val in tmpfmla:
if val in ['-', '+', '*', '/']:
op1 = stack.pop()
op2 = stack.pop()
if val == '-': result = op2 - op1
if val == '+': result = op2 + op1
if val == '*': result = op2 * op1
if val == '/':
if op1 == 0:
result = 1
else:
result = op2 / op1
stack.append(result)
treesize=treesize+1
else:
stack.append(float(val))
treesize = treesize - 1
if treesize>maxtreesize:
maxtreesize=treesize
if treesize<mintreesize:
mintreesize=treesize
return abs(mintreesize)
except:
print('error validate rpn>' + str(expression))
return 0
xxxx = ['x6', 'x7', '+', 'x7', '+', 'x7', '+', 'x7', '+']
print(getRPNdepth(xxxx))
def getRPNdepth(表达式):
treesize=0
maxtreesize=treesize
mintreesize=树大小
tmpexp=表达式
tmpfmla=[1如果n[0]='x'否则n代表tmpexp中的n]
打印(tmpfmla)
尝试:
堆栈=[]
对于tmpfmla中的val:
如果val在['-'、'+'、'*'、'/']中:
op1=stack.pop()
op2=stack.pop()
如果val='-':结果=op2-op1
如果val='+':结果=op2+op1
如果val='*':结果=op2*op1
如果val=='/':
如果op1==0:
结果=1
其他:
结果=op2/op1
stack.append(结果)
treesize=treesize+1
其他:
stack.append(float(val))
treesize=treesize-1
如果treesize>maxtreesize:
maxtreesize=treesize
如果treesize好的,只是做了一点“欺骗”,并使用我的rpn到中缀转换器来实现相同的目标,如果有人需要,我将它发布在这里
def getRPNdepth(expression):
tmpexp = expression
tmpfmla = [1 if n[0] == 'x' else n for n in tmpexp]
stack = []
for val in tmpfmla:
if val!=' ':
if val in ['-', '+', '*', '/']:
op1 = stack.pop()
op2 = stack.pop()
stack.append('(' + str(op1) + str(val) + str(op2) + ')')
else:
stack.append(str(val))
openparentesiscount=0
maxopenparentesiscount = 0
onlyparentesis=''
for c in stack[0]:
if c in ['(', ')']:
onlyparentesis=onlyparentesis+c
if c=='(':
openparentesiscount=openparentesiscount+1
else:
openparentesiscount = openparentesiscount - 1
if openparentesiscount>maxopenparentesiscount:
maxopenparentesiscount=openparentesiscount
return maxopenparentesiscount
谢谢大家 计算树深度与计算表达式类似,但运算符计算结果深度而不是结果值:
def getRPNdepth(expression):
stack = []
for val in expression:
if val in ['-', '+', '*', '/']:
stack.append(max(stack.pop(),stack.pop())+1)
else:
stack.append(1)
return stack.pop()
什么是“树的大小”?一般情况下,不应将mintreesize和maxtreesize初始化为相同的值。我称之为树大小的是树的深度。mittreesize和maxtreesize初始化为相同的值,因为树尚未“测量”