Stack Challenge #2 - Code Review!

📚 Official Books Data Structures & Algorithms in Swift
1

Can someone review if this code is valid as a solution? - The difference is that I’m not popping and I’m using 2 different counters. The time complexity is still linear O(n), right? + I’m still using stack methods. So approved or rejected? Thanks~

var testString1 = "h((e))llo(world)()"

func checkParentheses(_ string: String) -> Bool {
    
    // counter 1 for (
    var count1 = 0
    
    // counter 2 for )
    var count2 = 0
    
    // instantiate the stack
    var stack = Stack<Character>()
    
    // load the stack
    for value in string {
        
        if value == "(" {
            count1 += 1
        } else if value == ")" {
            count2 += 1
        }
        
        stack.push(value)
    }
    
    // check for empty
    if stack.isEmpty {
        print("Stack contains 0 elements")
        return false
    }
    
    //print both counters just out of curiosity 
    print(count1)
    print(count2)
    
    // Ternary operator
    return count1 == count2 ? true : false
    // check for success
    // check for failure
}

 checkParentheses(testString1) // should be true
2

@jomoka @kelvin_lau any thoughts?

3

I did it this way as well, although being new to Tim & space complexity I’m not sure if this is a good solution.

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