Python Coding Test Course, Helping the Less Fortunate

Coding tests are one of the essential skills required in the recent IT industry. It is necessary to deeply understand the core of the problem, rather than mechanically solving it, and to utilize the correct algorithms and data structures. In this course, we will select an algorithmic problem with the theme of helping the underprivileged and explain the process of solving that problem in detail.

Problem Description

The Helping the Underprivileged program simulates the process of gathering donations from donors to meet the amount needed by welfare organizations. Donors can contribute different amounts, and when the total amount of donations reaches a specific amount, the program must output the total amount of donations and the number of donors.

Problem Definition

Implement a program that satisfies the following conditions.

  • The number of donors is N. (1 ≤ N ≤ 100)
  • Each donor can contribute an amount of 1,000 or more.
  • Set a target amount M. (M is a natural number of 1,000 or more)

Input

The first line contains the number of donors N and the target amount M, separated by a space.

The second line contains the amounts each donor will contribute, separated by spaces.

Output

Print the total amount of donations and the number of donors. If the total amount is greater than or equal to M, also print the message “Target Achieved”.

Problem Solving Process

Now, let’s take a step-by-step look at the algorithm to solve the above problem.

Step 1: Problem Analysis

To solve the problem, we need to calculate the total amount of donations using the number of donors and the contribution amount from each donor provided as input. Then we check this total amount against the target amount M.

Step 2: Algorithm Design

The algorithm can be designed as follows:

  1. Input the number of donors N and the target amount M.
  2. Input the amounts donated by N donors as a list.
  3. Calculate the total amount of donations by summing all the elements in the list.
  4. If the total amount of donations is greater than or equal to M, output the total amount and the number of donors, including the message “Target Achieved”.
  5. If not, output only the total amount and the number of donors.

Step 3: Code Implementation

Now, let’s implement the code in Python based on the algorithm designed above.

    
def main():
    # Input the number of donors N and the target amount M
    N, M = map(int, input().split())
    
    # Input the list of amounts donated by donors
    donations = list(map(int, input().split()))
    
    # Calculate the total amount of donations
    total_donations = sum(donations)
    
    # Output the result
    print(f"Total Donations: {total_donations}, Number of Donors: {N}")
    
    # Compare with the target amount
    if total_donations >= M:
        print("Target Achieved")

if __name__ == "__main__":
    main()

Step 4: Code Explanation

The above code performs the following functions:

  • On the first line, it inputs the number of donors and the target amount, converting them to integers using the map function.
  • On the second line, it inputs and stores the donation amounts from each donor in a list.
  • It uses the sum() function to calculate the total amount of donations and outputs this amount.
  • It checks whether the total amount of donations meets or exceeds the target amount and outputs a message based on that check.

Step 5: Performance Review

The time complexity of this problem is O(N). Since the maximum number of donors is 100, this level of time complexity can be considered very efficient for coding tests. The space complexity is O(N) as a list is used to store donation amounts.

Step 6: Example and Test Cases

To increase the reliability of the code, various test cases have been prepared:

Test Case 1

Input:

    5 10000
    3000 4000 2000 5000 1500

Output:

    Total Donations: 15500, Number of Donors: 5
    Target Achieved

Test Case 2

Input:

    3 20000
    5000 6000 7000

Output:

    Total Donations: 18000, Number of Donors: 3

Through these various test cases, we can verify that the code works without issues.

Conclusion

In this course, we systematically examined the process of solving a Python algorithm problem with the theme of helping the underprivileged. I would like to emphasize the importance of accurately understanding the problem and progressively building the algorithm to solve it. This process is useful not only for coding tests but also in real development environments.

I hope you will continue to build your skills through various algorithm problems and develop your problem-solving abilities. Thank you.