Python Solution for Codeforces Problem 1851A - Escalator Conversations

Introduction

The world of competitive programming is a realm where logical thinking meets algorithmic challenges. Among these, Codeforces problem 1851A - Escalator Conversations, presents a scenario involving escalator discussions. In this article, we'll delve into an optimized Python solution for this problem, elucidating its mechanics, and underlining the value of the Codeforces platform in nurturing coding expertise.

Codeforces Problem 1851A - Escalator Conversations

Codeforces problem 1851A, aptly named "Escalator Conversations," challenges participants to evaluate possible conversations while riding an escalator. The problem prompts programmers to compute the count of potential discussions based on specified conditions.

Python Solution for Problem 1851A - Escalator Conversations

import math
T = int(input())
for _ in range(T):
    n, m, k, H = map(int, input().split())
    h = list(map(int, input().split()))
    cnt = 0
    for i in range(n):
        diff = abs(H - h[i])
        if diff % k == 0 and diff <= (k * (m - 1)) and diff != 0:
            cnt += 1
    print(cnt)

Explanation of the Python Code

1. Input and Iteration: The code initiates by reading an integer `T`, representing the number of test cases. A loop iterates `T` times to handle each test case.
2. Input and Data Extraction: For each test case, the code reads `n` (number of friends), `m` (number of escalator steps), `k` (step difference in conversation), and `H` (escalator height). Additionally, heights of individual friends are read into a list `h`.
3. Counting Conversations: The variable `cnt` is used to keep track of valid conversations. A loop traverses the list of friend heights (`h`). For each friend, the code calculates the absolute difference between the friend's height and the escalator height. The subsequent conditions ensure that the conversation difference is a multiple of `k`, within the range of permissible conversation steps, and not equal to zero.
4. Count Update and Output: If the conditions are met, the `cnt` variable is incremented, signifying a valid conversation. After evaluating all friends, the `cnt` value is printed as the count of feasible conversations.

Conclusion

Competitive programming is a playground where problem-solving proficiency flourishes, exemplified by Codeforces problem 1851A - Escalator Conversations. The Python solution disassembled above empowers programmers to adeptly compute potential conversations while riding an escalator. This coding endeavor underscores the importance of loop iteration and logical conditions in problem-solving.
Platforms like Codeforces cultivate an ideal environment for nurturing problem-solving abilities, refining coding efficiency, and participating in exhilarating coding contests. This article functions as a guide, illuminating the intricacies of the Escalator Conversations problem and paving the path toward mastering analogous algorithmic enigmas.
Embark on the captivating journey of competitive programming, fortified with a comprehensive understanding of core concepts. This expertise empowers you to gracefully conquer coding challenges, fostering an everlasting voyage of advancement and exploration. Happy coding and problem-solving!