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
Solution (Java)
class Solution {
public int totalMoney(int n) {
int mondayMoney = 1;
int total = 0;
while (n > 0) {
int weekDays = 0;
int base = mondayMoney;
while (weekDays < 7 && n > 0) {
total += base;
base++;
weekDays++;
n--;
}
mondayMoney++;
}
return total;
}
}
Explain:
nope.
Complexity:
- Time complexity : O(n).
- Space complexity : O(n).