Solution for Advent of code.. Day4 problem.

aoc_day4.py

class Stack:

    def __init__(self, n):
        self.array = []
        self.n = n

    def __len__(self):
        return len(self.array)

    def is_empty(self):
        return self.__len__() == 0
    
    def top(self):
        if self.is_empty():
            return 0
        return self.array[-1]
    
    def push(self, data):
        if self.__len__() > self.n:
            return 'OVERFLOW'
        self.array.append(data)
    
    def pop(self):
        if self.__len__() == 0:
            return "UNDERFLOW"
        temp = self.array[-1]
        del self.array[-1]
        return temp

    def clear_stack(self):
        self.array[:] = []


def range_rule(number):
    s = Stack(6)
    flag = 0
    number_set = set(number)
    #if bool(list(filter(lambda x: number.count(x)>1, number_set))):        # Use of filter expression
    
    if any(number.count(i) > 1 for i in number_set):        # For part1
    #if any(number.count(i) == 2 for i in number_set):      # For part2 
        for i in number:
            if s.top() <= int(i):           # Meet 1st criteria
                s.push(int(i))
        
            else:
                s.clear_stack()
                break

            if s.__len__() == 6:
                flag += 1
    return flag


if __name__ == "__main__":
    total = 0
    for i in range(372304, 847060):
        total += range_rule(str(i))

    print(total