NEED HELP WITH THIS (DO IT IN JAVA PLEASE) Consider an expression that contains

Question

NEED HELP WITH THIS (DO IT IN JAVA PLEASE)

Consider an expression that contains grouping symbols. The grouping symbols are parentheses, { }, [ ]. Expressions are considered to be balanced if their grouping symbols follow the following rules:

each left symbol must be followed by a right symbol with some data in between (ie. you can't have an empty pair like [ ] )

if pairs are nested , one pair must be completely nested within another.

Here is an example of a balanced expression: abc{de(fg){ijk}{l{m[n]}}o[p]}qr

Here is an example where the grouping symbols are not balanced: abc{(def}}{ghij{kl}m]

Write a method with signature boolean isBalanced(String s) that returns true if the grouping symbols within the string are properly balanced. Use a stack in your solution. You may assume that each symbol is just one character and that there are no spaces, as in the examples above.

Explanation / Answer

import java.util.*;

public class ParenthesisMatching
{
//function to check Balanced
public static boolean Balanced(String s) {
HashMap<Character, Character> map = new HashMap<Character, Character>();
map.put('(', ')');
map.put('[', ']');
map.put('{', '}');

Stack<Character> stack = new Stack<Character>();

for (int i = 0; i < s.length(); i++) {
char curr = s.charAt(i);

if (map.keySet().contains(curr)) {
stack.push(curr);
} else if (map.values().contains(curr)) {
if (!stack.empty() && map.get(stack.peek()) == curr) {
stack.pop();
} else {
return false;
}
}
}

return stack.empty();
}
public static void main(String[] args)
{
Scanner sc=new Scanner(System.in);
String s=sc.next();
boolean flag=Balanced(s);
if(flag)
System.out.println("Balanced");
else
System.out.println("Not Balanced");
  
}
}

==============================================================================

Output:

akshay@akshay-Inspiron-3537:~/Chegg$ javac ParenthesisMatching.java
akshay@akshay-Inspiron-3537:~/Chegg$ java ParenthesisMatching
abc{de(fg){ijk}{l{m[n]}}o[p]}qr
Balanced

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