Dollar Sign Deletion

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Description

You're given an array of strings containing alphabetical characters and certain $ characters. A $ represents a DELETE action whereby the character before it is deleted.

Each of these strings will be run through a method to operate on the $ DELETE action. We want to find out if the final string is the same for all of them. Let's take an example:

String[] input = {"f$st", "st"};
isDollarDeleteEqual(input);
// true
// true because both become "st"

let input = ["f$st", "st"];
isDollarDeleteEqual(input);
// true
// true because both become "st"

input = ["f$st", "st"]
is_dollar_delete_equal(input)
# True
# True because both become 'st'

std::vector<std::string> input = {"f$st", "st"};
isDollarDeleteEqual(input);
// true
// true because both become "st"

string[] input = {"f$st", "st"};
IsDollarDeleteEqual(input);
// true
// true because both become "st"

input := []string{"f$st", "st"}
isDollarDeleteEqual(input)
// true
// true because both become "st"

Can you find a solution in O(n) time and constant space?

Constraints

The input arrays can be of any size
Every string has at least a single character
The string will consist of dollar signs and lowercase alphabets
Expected overall time complexity : O(n)
Expected space complexity : O(n) for good solution, O(1) for asymptotically optimal solution

```js
function isDollarDeleteEqual(arr) {
  // Fill in this method
  return arr;
}

function getFinalStr(str) {
  // Fill in this method
  return str;
}

// const input = ["f$st", "st"];
// console.log(isDollarDeleteEqual(input));
```
```java
public boolean isDollarDeleteEqual(String[] arr) {
  // Fill in this method
  return arr;
}

public String getFinalStr(String str) {
  // Fill in this method
  return str;
}

// String[] input = {"f$st", "st"};
// System.out.println(isDollarDeleteEqual(input));
```
```python
def is_dollar_delete_equal(arr):
  # Fill in this method
  return arr

def get_final_str(str):
  # Fill in this method
  return str

# input_arr = ["f$st", "st"]
# print(is_dollar_delete_equal(input_arr))
```
```cpp
bool isDollarDeleteEqual(string arr[]) {
  // Fill in this method
  return arr;
}

string getFinalStr(string str) {
  // Fill in this method
  return str;
}

//string input[] = {"f$st", "st"};
//cout << isDollarDeleteEqual(input);
```
```csharp
public bool IsDollarDeleteEqual(string[] arr) {
  // Fill in this method
  return arr;
}

public string GetFinalStr(string str) {
  // Fill in this method
  return str;
}

// string[] input = {"f$st", "st"};
// Console.WriteLine(IsDollarDeleteEqual(input));
```
```go
func isDollarDeleteEqual(arr []string) []string {
  // Fill in this method
  return arr
}

func getFinalStr(str string) string {
  // Fill in this method
  return str
}

//input := []string{"f$st", "st"}
//fmt.Println(isDollarDeleteEqual(input))
```

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