My issue
My code
/* package codechef; // don't place package name! */
import java.util.*;
import java.lang.*;
import java.io.*;
/* Name of the class has to be "Main" only if the class is public. */
class Codechef
{
public static void main (String[] args) throws java.lang.Exception
{
Scanner sc = new Scanner(System.in);
int t = sc.nextInt();
while(t-->0){
int n = sc.nextInt();
String s = sc.next();
Stack<Character> b = new Stack<>();
for(int i = 0; i<n; i++){
if(s.charAt(i)=='.'){
continue;
}
else if(s.charAt(i)=='H') {
b.push(s.charAt(i));
}
else if(s.charAt(i)=='T'){
if(b.size() == 1){
b.pop();
// System.out.println("BLock3 "+i);}
}
}
}
if(b.isEmpty()){
System.out.println("Valid");
}
else
System.out.println("Invalid");
}
}
}
Problem Link: SNAKPROC Problem - CodeChef