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$ curl repovive.com/roadmaps/data-structures/stacks-monotonic-stacks/valid-parentheses-implementation

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$ curl repovive.com/roadmaps/data-structures/stacks-monotonic-stacks/valid-parentheses-implementation

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Valid Parentheses - Implementation - Stacks & Monotonic Stacks | Data Structures | Repovive

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Data Structures19 sections · 729 units49h total

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Valid Parentheses - Implementation

Complete solution

Here's the solution:

function isValid(s)
    stack := empty stack
    matchingBracket := {'(': ')', '{': '}', '[': ']'}

    for each char in s
        if char is in matchingBracket  // it's an open bracket
            push char onto stack
        else  // it's a close bracket
            if stack is empty
                return false
            top := pop from stack
            if matchingBracket[top] != char
                return false

    return stack is empty

Time: $O(n)$ . Space: $O(n)$ in the worst case.