Calculate Money in Leetcode Bank
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Reviewed by Calculator Editorial Team
LeetCode Bank is a problem where you need to calculate the total amount of money you can save in a bank over a certain number of days. This calculator helps you determine the total amount based on the number of days you plan to save.
What is LeetCode Bank?
The LeetCode Bank problem is a coding challenge that simulates a savings plan where you deposit money into a bank each day. The amount you deposit increases by $1 each day. For example, on day 1 you deposit $1, on day 2 you deposit $2, and so on.
This problem tests your understanding of loops, conditional statements, and basic arithmetic operations in programming. It's a common interview question for software engineering positions.
How to Calculate Money in LeetCode Bank
To calculate the total amount of money you'll have in the LeetCode Bank after n days, you need to sum the series of deposits from day 1 to day n. The deposits form an arithmetic series where each term increases by $1.
The formula for the sum of the first n natural numbers is:
Formula
Total Money = n × (n + 1) / 2
Where:
- n = number of days
This formula works because the deposits form a triangular number pattern.
Example Calculation
Let's say you want to calculate the total money after 5 days:
- Day 1: $1
- Day 2: $2
- Day 3: $3
- Day 4: $4
- Day 5: $5
The total money would be: 1 + 2 + 3 + 4 + 5 = $15
Using the formula: 5 × (5 + 1) / 2 = 5 × 6 / 2 = 15
Formula
Total Money in LeetCode Bank
Total Money = n × (n + 1) / 2
Where:
- n = number of days
This formula efficiently calculates the sum of the arithmetic series without needing to iterate through each day individually.
FAQ
What is the time complexity of this calculation?
The time complexity is O(1) because it uses a direct formula to calculate the result without any loops or iterations.
Can I use this formula for any number of days?
Yes, the formula works for any positive integer value of n (number of days).
Is this problem only about arithmetic series?
Yes, the LeetCode Bank problem specifically focuses on calculating the sum of an arithmetic series where each term increases by $1.