## 1652. Defuse the Bomb

You have a bomb to defuse, and your time is running out! Your informer will provide you with a **circular** array `code`

of length of `n`

and a key `k`

.

To decrypt the code, you must replace every number. All the numbers are replaced **simultaneously**.

- If
`k > 0`

, replace the`i`

number with the sum of the^{th}**next**`k`

numbers. - If
`k < 0`

, replace the`i`

number with the sum of the^{th}**previous**`k`

numbers. - If
`k == 0`

, replace the`i`

number with^{th}`0`

.

As `code`

is circular, the next element of `code[n-1]`

is `code[0]`

, and the previous element of `code[0]`

is `code[n-1]`

.

Given the **circular** array `code`

and an integer key `k`

, return *the decrypted code to defuse the bomb*!

**Example 1:**

Input:code = [5,7,1,4], k = 3Output:[12,10,16,13]Explanation:Each number is replaced by the sum of the next 3 numbers. The decrypted code is [7+1+4, 1+4+5, 4+5+7, 5+7+1]. Notice that the numbers wrap around.

**Example 2:**

Input:code = [1,2,3,4], k = 0Output:[0,0,0,0]Explanation:When k is zero, the numbers are replaced by 0.

**Example 3:**

Input:code = [2,4,9,3], k = -2Output:[12,5,6,13]Explanation:The decrypted code is [3+9, 2+3, 4+2, 9+4]. Notice that the numbers wrap around again. If k is negative, the sum is of thepreviousnumbers.

**Constraints:**

`n == code.length`

`1 <= n <= 100`

`1 <= code[i] <= 100`

`-(n - 1) <= k <= n - 1`

## Rust Solution

```
struct Solution;
impl Solution {
fn decrypt(code: Vec<i32>, k: i32) -> Vec<i32> {
let n = code.len();
if k == 0 {
return vec![0; n];
}
let mut res = vec![];
for i in 0..n {
let mut sum = 0;
for j in 0..k.abs() {
let index = if k > 0 {
(n as i32 + (i as i32 + 1 + j)) as usize % n
} else {
(n as i32 + (i as i32 - 1 - j)) as usize % n
};
sum += code[index];
}
res.push(sum);
}
res
}
}
#[test]
fn test() {
let code = vec![5, 7, 1, 4];
let k = 3;
let res = vec![12, 10, 16, 13];
assert_eq!(Solution::decrypt(code, k), res);
let code = vec![1, 2, 3, 4];
let k = 0;
let res = vec![0, 0, 0, 0];
assert_eq!(Solution::decrypt(code, k), res);
let code = vec![2, 4, 9, 3];
let k = -2;
let res = vec![12, 5, 6, 13];
assert_eq!(Solution::decrypt(code, k), res);
}
```

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