1716. Calculate Money in Leetcode Bank

Problem

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 nth day.

Example 1:

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

Example 2:

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

Example 3:

Input: n = 20
Output: 96
Explanation: After the 20th 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

Problem Summary

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. From Tuesday to Sunday, he puts in $1 more than the day before. On every subsequent Monday, he puts in $1 more than the previous Monday. Given n, return the total amount of money he has in the Leetcode bank at the end of the nth day.

Solution Approach

• Easy problem. Just write 2 nested loops according to the problem statement.

Code

package leetcode

func totalMoney(n int) int {
	res := 0
	for tmp, count := 1, 7; n > 0; tmp, count = tmp+1, 7 {
		for m := tmp; n > 0 && count > 0; m++ {
			res += m
			n--
			count--
		}
	}
	return res
}