pacman

def uniformCostSearch(problem):
    """Search the node of least total cost first."""
    "*** YOUR CODE HERE ***"
    fringe = util.PriorityQueue()
    generated = {}
    n = node.Node(problem.getStartState(), None, None, 0)
    fringe.push(n, n.pathcost) #COMPROBAR SI ES UN ESTADO SOLUCION
    generated[n.state] = [n, 'F']
    while True:
        if fringe.isEmpty():
            sys.exit("failure")
        n = fringe.pop()
        if problem.isGoalState(n.state):
        return ns.path() #COMPROBAR QUE NO ESTA EN EL FRINGE
    if n.state in generated:
        if generated[n.state] != 'E':
                generated[n.state] = [n, 'E']
                for suc, action, cost in problem.getSuccessors(n.state):
                ns=node.Node(suc, n, action, n.pathcost + cost)
                    if suc not in generated:
                    fringe.push(ns, ns.pathcost)
                    generated[ns.state] = [ns, 'F']
                elif n.pathcost > ns.pathcost:
                    fringe.push(ns, ns.pathcost)
                    generated[ns.state] = [ns, 'F']
    util.raiseNotDefined()