def uniformCostSearch(problem):
    fridges = util.PriorityQueue()
    fridges.push([[problem.getStartState(), 'Start', 0]], 0)
    visited = [problem.getStartState()]

    while not fridges.isEmpty():
        fridge = fridges.pop()
        state, dir, cost = fridge[-1]

        if (problem.isGoalState(state)):
            path = []

            for state, dir, cost in fridge:
                path.append(dir)

            path.remove('Start');
            return path

        visited.append(state)
        newStates = problem.getSuccessors(state)
        for newState, newDir, newCost in newStates:
            if (visited.count(newState) == 0):
                fridges.push(fridge + [[newState, newDir, newCost]], cost + newCost)