## 1716. Calculate Money in Leetcode Bank

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`

## Rust Solution

``````struct Solution;

impl Solution {
fn total_money(n: i32) -> i32 {
let mut res = 0;
for i in 0..n {
res += (i % 7) + (i / 7) + 1;
}
res
}
}

#[test]
fn test() {
let n = 4;
let res = 10;
assert_eq!(Solution::total_money(n), res);
let n = 10;
let res = 37;
assert_eq!(Solution::total_money(n), res);
let n = 20;
let res = 96;
assert_eq!(Solution::total_money(n), res);
}
``````

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