Single Number II

Given an integer array nums where every element appears three times except for one, which appears exactly once. Find the single element and return it.

You must implement a solution with a linear runtime complexity and use only constant extra space.

 

Example 1:

Input: nums = [2,2,3,2]
Output: 3

Example 2:

Input: nums = [0,1,0,1,0,1,99]
Output: 99

 

Constraints:

  • 1 <= nums.length <= 3 * 104
  • -231 <= nums[i] <= 231 - 1
  • Each element in nums appears exactly three times except for one element which appears once.
SOLUTION:
import bisect

class Solution:
    def singleNumber(self, nums: List[int]) -> int:
        nums.sort()
        numset = set(nums)
        for num in numset:
            if bisect.bisect_left(nums, num) + 1 == bisect.bisect_right(nums, num):
                return num

Comments

Post a Comment

Popular posts from this blog

Lazy Deletion in Heap: A Wrapper for Python heapq

Lazy Deletion in Heap: A Wrapper for Python heapq Lazy Deletion in Heap: A Wrapper for Python heapq In many programming scenarios, we often encounter situations where we need to maintain a heap data structure and perform operations such as insertion, deletion, and retrieval of the minimum element efficiently. Python provides a built-in module called heapq that offers heap operations. However, the standard heapq module does not provide direct support for lazy deletion, which can be useful in certain cases. In this article, we will explore a wrapper class, Heap , that extends the functionality of the Python heapq library to support lazy deletion in a heap. The Heap Class The Heap class is a wrapper that encapsulates the heapq module to enable lazy deletion in a heap. Let's go through its main methods and their functionalities: __init__(self) : Initializes the Heap instance by creating an empty heap and a defaultdict to track the deleted elements ...
Read more

Efficient Generation of Nth Row of Binomial Coefficient Modulo M

Efficient Generation of Nth Row of Binomial Coefficient Modulo M Efficient Generation of Nth Row of Binomial Coefficient Modulo M Introduction Calculating the binomial coefficient (also known as the combinatorial coefficient) is a common task in mathematics and programming. However, when the modulo M is not prime, finding an efficient method becomes more challenging. In this article, we will explore a technique that allows us to efficiently generate the Nth row of the binomial coefficient modulo M, even when M is not necessarily prime. This technique utilizes prime factorization and a sieve algorithm to achieve efficient computation. The Implementation Let's take a look at the implementation of the technique: from collections import Counter N = 1 + 10 ** 6 v = [False] * N spf = [1] * N for i in range(2, N, 2): spf[i] = 2 for i in range(3, N, 2): if not v[i]: spf[i] = i j = i while j * i 1: ctr[spf[a]...
Read more

Sliding Window GCD

Sliding Window GCD Sliding Window GCD Problem Description You are given an array of integers nums of length N . There is a sliding window of size k which is moving from the very left of the array to the very right. You can only see the k numbers in the window. Each time the sliding window moves right by one position. Return an array of length N - k + 1 representing the GCD of each subarray of length k from left to right. Solution Approach The solution to this problem involves implementing a special queue data structure using two stacks. This special queue allows the push , pop , and GCD operations in O(1) amortized time complexity. The implementation of this queue is based on the combination of two existing techniques: implementing a queue using stacks and implementing a stack that stores GCD values. By using this special queue, we can efficiently calculate the GCD for each sliding window in O(N) time complexity. This technique is useful to understand the impl...
Read more