Good morning! Here's our prompt for today.

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:

1input := []string{"f$st", "st"}
2isDollarDeleteEqual(input)
3// true
4// 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

Try to solve this here or in Interactive Mode.

How do I practice this challenge?

xxxxxxxxxx

​

package main

​

import (

  "fmt"

)

​

func isDollarSignEqual(slice []string) bool {

  // fill in this function

  return true

}

func main() {

  slice := []string{"b$$p", "$b$p"}

  fmt.Println(isDollarSignEqual(slice))

​

  // test cases start

  fmt.Printf("============================================================\n")

  passed := true

  if isDollarSignEqual([]string{"f$ec", "ec"}) == true {

    fmt.Println("TEST 1 --- PASSED")

  } else {

    fmt.Println("TEST 1 --- FAILED : got ", isDollarSignEqual([]string{"f$ec", "ec"}), " expected true")

    passed = false

  }

  if isDollarSignEqual([]string{"a90$n$c$se", "a90n$cse"}) == false {

    fmt.Println("TEST 2 --- PASSED")

  } else {

    fmt.Println("TEST 2 --- FAILED : got ", isDollarSignEqual([]string{"a90$n$c$se", "a90n$cse"}), " expected false")

    passed = false

  }

Here's our guided, illustrated walk-through.

How do I use this guide?