Question

How to check if a string contains only valid parentheses (open close same type (), {}, []) in Java

Answer 1

import java.util.ArrayDeque;
import java.util.Deque;

class Program {
    static boolean string_contains_valid_parentheses(String s) {
        Deque<Character> stack = new ArrayDeque<>();
    
        for (final char ch : s.toCharArray()) {
            if (ch == '(') {
                stack.push(')');
            }
            else if (ch == '{') {
                stack.push('}');
            }
            else if (ch == '[') {
                stack.push(']');
            }
            else if (stack.isEmpty() || stack.pop() != ch) {
                    return false;
            }
        }
    
        return stack.isEmpty();
    }
    
    public static void main(String[] args) {
        System.out.println(string_contains_valid_parentheses("(){}[]()(){}"));
    }
}



/*
run:
 
true
 
*/

 

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