170_Two Sum III - Data Structure Design

Level: easy

Tag: array

Question

Design and implement a TwoSum class. It should support the following operations: add and find.

add - Add the number to an internal data structure.
find - Find if there exists any pair of numbers which sum is equal to the value.

Idea

Solution

class TwoSum(object):

    def __init__(self):
        """
        Initialize your data structure here.
        """
        self.dic = {}


    def add(self, number):
        """
        Add the number to an internal data structure..
        :type number: int
        :rtype: void
        """
        if number in self.dic:
            self.dic[number] += 1
        else:
            self.dic[number] = 1


    def find(self, value):
        """
        Find if there exists any pair of numbers which sum is equal to the value.
        :type value: int
        :rtype: bool
        """
        dic = self.dic
        for num in dic:
            if value - num in dic and (value - num != num or dic[num] > 1):
                return True
        return False



# Your TwoSum object will be instantiated and called as such:
# obj = TwoSum()
# obj.add(number)
# param_2 = obj.find(value)