mirror of
https://github.com/heqin-zhu/algorithm.git
synced 2024-03-22 13:30:46 +08:00
237 lines
7.5 KiB
Python
237 lines
7.5 KiB
Python
from collections import Iterable,deque
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class vertex:
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def __init__(self,mark,val=None ,firstEdge = None):
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self.mark = mark
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self.val = val
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self.firstEdge = firstEdge
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self.isVisited = False
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def __str__(self):
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if '0'<=self.mark[0]<='9':return 'v'+str(self.mark)
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return str(self.mark)
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def __repr__(self):
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li=[]
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arc= self.firstEdge
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while arc!=None:
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li.append(arc)
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arc= arc.outNextEdge
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return str(self)+ ' to:'+str([str(i.inArrow) for i in li])
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class edge:
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def __init__(self,outArrow,inArrow,outNextEdge = None,inNextEdge = None, weight = 1):
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self.weight = weight
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self.inNextEdge = inNextEdge
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self.outNextEdge = outNextEdge
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self.outArrow = outArrow
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self.inArrow=inArrow
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self.isVisited = False
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def __str__(self):
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return '--'+str(self.weight)+'-->'
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def __repr__(self):
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return str(self)
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class graph:
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def __init__(self):
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self.vertexs = {}
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self.edges = {}
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def __getitem__(self,i):
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return self.vertexs[i]
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def __setitem__(selfi,x):
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self.vertexs[i]= x
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def __iter__(self):
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return iter(self.vertexs.values())
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def __bool__(self):
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return len(self.vertexs)!=0
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def addVertex(self,vertexs):
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'''vertexs is a iterable or just a mark that marks the vertex,whichc can be every imutable type'''
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if not isinstance(vertexs,Iterable):vertexs=[vertexs]
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for i in vertexs:
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if not isinstance(i,vertex) and i not in self.vertexs:self.vertexs[i]= vertex(i)
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if isinstance(i,vertex) and i not in self.vertexs:self.vertexs[i.mark]= i
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def isConnected(self,v,u):
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v = self.__getVertex(v)
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u = self.__getVertex(u)
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arc= v.firstEdge
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while arc!=None:
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if arc.inArrow==u:return True
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arc = arc.inNextEdge
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return False
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def __getVertex(self,v):
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if not isinstance(v,vertex):
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if v not in self.vertexs:
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self.vertexs[v]=vertex(v)
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return self.vertexs[v]
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return v
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def addEdge(self,v,u,weight = 1):
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v = self.__getVertex(v)
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u = self.__getVertex(u)
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arc = v.firstEdge
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while arc!=None: #examine that if v,u have been already connected
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if arc.inArrow==u: return
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arc= arc.outNextEdge
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newEdge = edge(v,u,v.firstEdge,u.firstEdge,weight)
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self.edges[(v.mark,u.mark)] = newEdge
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v.firstEdge = newEdge
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def delEdge(self,v,u):
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if not isinstance(v,vertex):v= self.vertexs[v]
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if not isinstance(u,vertex):u= self.vertexs[u]
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self._unrelated(v,u)
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del self.edges[(v.mark,u.mark)]
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def _unrelated(self,v,u):
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if v.firstEdge==None:return
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if v.firstEdge.inArrow == u:
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v.firstEdge =v.firstEdge.outNextEdge
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else:
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arc = v.firstEdge
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while arc.outNextEdge!=None:
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if arc.outNextEdge.inArrow ==u:
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arc.outNextEdge = arc.outNextEdge.outNextEdge
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break
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def revisit(self):
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for i in self.vertexs:
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self.vertexs[i].isVisited=False
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for i in self.edges:
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self.edges[i].isVisited=False
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def __str__(self):
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arcs= list(self.edges.keys())
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arcs=[str(i[0])+'--->'+str(i[1])+' weight:'+str(self.edges[i].weight) for i in arcs]
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s= '\n'.join(arcs)
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return s
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def __repr__(self):
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return str(self)
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def notIn(self,v):
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if (isinstance(v,vertex) and v.mark not in self.vertexs) or v not in self.vertexs:
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return True
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return False
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def visitPath(self,v,u):
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'''bfs'''
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if self.notIn(v) or self.notIn(u):
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return None,None
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v = self.__getVertex(v)
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u = self.__getVertex(u)
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if v.firstEdge==None:return None,None
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q=deque([v.firstEdge])
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isFind=False
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vs,es=[],[]
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while len(q)!=0:
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vs,es=[],[]
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arc= q.popleft()
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if arc.outNextEdge!=None and not arc.outNextEdge.isVisited:q.append(arc.outNextEdge)
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while arc!=None:
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if arc.isVisited:break
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arc.isVisited=True
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es.append(arc)
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vs.append(arc.inArrow)
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arc.outArrow.isVisited=True
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if arc.inArrow==u:
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isFind=True
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break
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arc = arc.inArrow.firstEdge
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# very important , avoid circle travel
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while arc.inArrow.isVisited and arc.outNextEdge:arc = arc.outNextEdge
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if isFind:break
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else:return None,None
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'''
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se = [str(i) for i in es]
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sv = [str(i) for i in vs]
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print(str(v),end='')
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for i,j in zip(se,sv):
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print(i,j,end='')
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'''
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return vs,es
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def hasVertex(self,mark):
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return mark in self.vertexs
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def display(self):
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print('vertexs')
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for i in self.vertexs:
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print(self.vertexs[i].__repr__())
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print('edges')
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for i in self.edges:
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arc=self.edges[i]
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print(str(arc.outArrow)+str(arc)+str(arc.inArrow))
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class Solution(object):
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def calcEquation(self, equations, values, queries):
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"""
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:type equations: List[List[str]]
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:type values: List[float]
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:type queries: List[List[str]]
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:rtype: List[float]
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"""
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rst =[]
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g= graph()
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for edge,wt in zip(equations,values):
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g.addEdge(edge[0],edge[1],wt)
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g.addEdge(edge[1],edge[0],1/wt)###### to serach quickly but sacrifacing some space
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g.display()
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for i in queries:
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if i[0]==i[1]:
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if i[0] in g.vertexs:rst.append(1.0)
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else:rst.append(-1.0)
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continue
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_,path = g.visitPath(i[0],i[1])
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if path==None:
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if not path:rst.append(-1.0)
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else:
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mul = 1
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for i in path:mul*=i.weight
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rst.append(mul)
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g.revisit()
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return rst
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if __name__=='__main__':
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equations = [["a","b"],["e","f"],["b","e"]]
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values = [3.4,1.4,2.3]
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queries = [["b","a"],["a","f"],["f","f"],["e","e"],["c","c"],["a","c"],["f","e"]]
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sol = Solution()
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ret=sol.calcEquation( equations, values, queries)
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print(ret)
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'''
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[0.29411764705882354, 10.947999999999999, 1.0, 1.0, -1.0, -1.0, 0.7142857142857143]
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'''
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'''
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equations = [ ["a", "b"], ["b", "c"] ]
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values = [2.0, 3.0]
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queries = [ ["a", "c"], ["b", "a"], ["a", "e"], ["a", "a"], ["x", "x"] ]
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sol = Solution()
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ret=sol.calcEquation( equations, values, queries)
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print(ret)
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'''
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'''
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[6.0, 0.5, -1.0, -1.0, -1.0]
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'''
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'''
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g = graph()
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g.addEdge(1,2)
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g.addEdge(2,1)
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g.addEdge(3,1)
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g.addEdge(1,4)
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g.addEdge(3,2)
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g.addEdge(2,4)
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g.addVertex(6)
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g.addEdge(4,6)
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g.delEdge(1,2)
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g.display()
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g.visitPath(3,6)
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'''
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'''
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vertexs
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v1 to:['v4']
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v2 to:['v4', 'v1']
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v3 to:['v2', 'v1']
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v4 to:['v6']
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v6 to:[]
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edges
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v2--1-->v1
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v3--1-->v1
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v1--1-->v4
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v3--1-->v2
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v2--1-->v4
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v4--1-->v6
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>>>
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'''
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