Balanced Parenthesis

☞ Check whether string is a balanced parenthesized expression.
Sample Input1
(()())
Sample Output1
Valid
Sample Input2
(()()
Sample Output2
Invalid

SOURCE CODE:

import java.io.*;

import java.util.*;

class BalancedParenthesis{

public static void main(String args[]){

    String str;

    int i,j=0,count=0;

    Scanner in = new Scanner(System.in);

    str = in.nextLine();

char top[] = new char[str.length()];

for(i=0;i<str.length();i++){

        if(str.charAt(i)=='(')

            top[j++]=str.charAt(i);

        else if(str.charAt(i)==')' && top[j-1]=='(')

            j--;

    }

    if(j==0)

        System.out.print("Valid");

    else

        System.out.print("Invalid");

}

}