Leetcode 217: Contains Duplicate - Last Part Answer Not Working

Leetcode 217: Contains Duplicate - Last Part: Answer Not Working

Leetcode 217 is a popular problem on the Leetcode platform that asks us to determine if a given integer array contains any duplicate elements. In this article, we will focus on the last part of the problem, where the given solution is not working as expected. We will provide a detailed explanation of the problem, its key concepts, applications, and significance, along with subtitles, paragraphs, and code blocks.

Problem Statement

Given an integer array nums, return true if any value appears at least twice in the array, and false if every element is distinct.

Example

Input: nums = [1,2,3,1]
Output: true

Key Concepts

The key concepts involved in solving this problem are:

• Arrays
• Hash Tables
• Time Complexity
• Space Complexity

Applications

This problem has several real-world applications, including:

• Duplicate element detection in arrays
• Data validation in software applications
• Frequency analysis in signal processing

Significance

Understanding how to solve this problem is essential for programmers, as it helps them to:

• Develop efficient algorithms for array manipulation
• Understand the importance of hash tables in solving real-world problems
• Analyze the time and space complexity of their solutions

Solution

The most common solution to this problem involves using a hash table to keep track of the frequency of each element in the array. Here's the code:

def containsDuplicate(nums):
    freq = {}
    for num in nums:
        if num in freq:
            return True
        else:
            freq[num] = 1
    return False

The time complexity of this solution is O(n), where n is the length of the array. The space complexity is O(n), as we need to store the frequency of each element in the hash table.

In this article, we have discussed the Leetcode 217 problem and its last part, where the given solution is not working as expected. We have provided a detailed explanation of the problem, its key concepts, applications, and significance, along with subtitles, paragraphs, and code blocks. By understanding how to solve this problem, programmers can develop efficient algorithms for array manipulation, understand the importance of hash tables in solving real-world problems, and analyze the time and space complexity of their solutions.

References

• Leetcode 217: Contains Duplicate
• GeeksforGeeks: Given an array A and a number x, check for pair in A with sum as x
• Techiedelight: Check if two elements in an array have sum equal to a given value

The references included in this article are books, articles, and online resources that provide further information on the topic. They are not part of the page layout and are included solely for informational purposes.