1716. Calculate Money in Leetcode Bank

Easy
​
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

解題

Runtime: 0 ms, faster than 100.00%
Memory Usage: 1.9 MB, less than 14.29%
func totalMoney(n int) int {
ans := 0
allday := 1
day := 1
week := 0
for allday <= n {
if day > 7 {
day = 1
week++
}
ans += day + week
day++
allday++
}
return ans
}