Is Calculate Money in Leetcode Bank easy or hard?

Calculate Money in Leetcode Bank is classified as an Easy problem on LeetCode with an acceptance rate above 80%. It mainly tests basic iteration, arithmetic patterns, and simple mathematical optimization.

Calculate Money in Leetcode Bank Python/Java solution

Both Python and Java implementations follow the same logic. You can either simulate deposits day by day using a loop or compute the result directly using the arithmetic formula for weekly sums. The mathematical approach runs in O(1) time and is typically the preferred implementation.

How to solve Calculate Money in Leetcode Bank in O(1)?

First compute full weeks w = n / 7 and remaining days r = n % 7. Each week forms an arithmetic sequence where the starting value increases by one. Sum all full weeks using arithmetic series formulas, then add the deposits for the remaining r days starting from w + 1. This reduces the problem to constant-time arithmetic operations.

What is the best approach for Calculate Money in Leetcode Bank?

The mathematical formula approach is the best solution. It computes the total savings in O(1) time by calculating the sum of full weeks using an arithmetic progression and then adding the remaining days. This avoids iterating through all n days and demonstrates pattern recognition.

Is Calculate Money in Leetcode Bank asked at Google/Amazon/Meta?

This problem is categorized as Easy and mainly tests basic math and pattern recognition. While it is less common in top-tier interview rounds, similar arithmetic pattern problems appear in coding screens and practice sets used by companies like Amazon and Google.

What data structure is used in Calculate Money in Leetcode Bank?

No specialized data structure is required. The problem is solved using simple integer variables and arithmetic calculations. It mainly relies on mathematical reasoning and optional loop-based simulation.

What is the time complexity of Calculate Money in Leetcode Bank?

Two common solutions exist. The simulation approach runs in O(n) time by iterating through each day and adding the deposit. The optimized mathematical approach runs in O(1) time because it directly computes the sum using arithmetic formulas for weekly deposits.

Description Hints 1 Solution Video 14:34

1716. Calculate Money in Leetcode Bank

Easy82.4% acceptance4 companies

Hercy wants to save money for his first car. He puts money in the Leetcode bank every day.

He starts by putting in $1 on Monday, the first day. Every day from Tuesday to Sunday, he will put in $1 more than the day before. On every subsequent Monday, he will put in $1 more than the previous Monday.

Given n, return the total amount of money he will have in the Leetcode bank at the end of the n^th day.

Example 1:

Input: n = 4
Output: 10
Explanation: After the 4^th day, the total is 1 + 2 + 3 + 4 = 10.

Example 2:

Input: n = 10
Output: 37
Explanation: After the 10^th day, the total is (1 + 2 + 3 + 4 + 5 + 6 + 7) + (2 + 3 + 4) = 37. Notice that on the 2^nd Monday, Hercy only puts in $2.

Example 3:

Input: n = 20
Output: 96
Explanation: After the 20^th day, the total is (1 + 2 + 3 + 4 + 5 + 6 + 7) + (2 + 3 + 4 + 5 + 6 + 7 + 8) + (3 + 4 + 5 + 6 + 7 + 8) = 96.

Constraints:

1 <= n <= 1000

Asked at 4 companies

Google Microsoft Amazon Meta

Topics

Math

Hints open one at a time

Hint 1

Simulate the process by keeping track of how much money Hercy is putting in and which day of the week it is, and use this information to deduce how much money Hercy will put in the next day.

14:34

Still stuck?Read 3 approaches, or watch a walkthrough.

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