Valid Parentheses in Java: Explanation & Practice

Check if parentheses string is valid

Problem summary

Given a string containing just '(', ')', '{', '}', '[', ']', determine if the input string is valid. Use stack!

Starter code

public class Main {
    public static void main(String[] args) {
        String s = "([{}])";
        
        // Push opening brackets onto stack
        // For closing brackets, check if matches top
        // Stack should be empty at end
        // Print: Is valid: true
    }
}

Expected output and test cases

([{}])
```
Is valid: true
```
([)]
```
Is valid: false
```
```
Is valid: true
```

Hints

Push opening brackets onto stack
For closing bracket, pop and check if it matches
If stack empty when trying to pop, invalid
After processing, stack should be empty

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