Day76

//Day76

//A. Do Not Be Distracted!
//
import java.util.HashSet;
import java.util.Scanner;

public class PolycarpTasks {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int t = scanner.nextInt(); // Number of test cases
        scanner.nextLine(); // Consume newline

        for (int i = 0; i < t; i++) {
            int n = scanner.nextInt(); // Number of days
            String tasks = scanner.next(); // Task sequence
            scanner.nextLine(); // Consume newline

            if (isSuspicious(tasks)) {
                System.out.println("NO");
            } else {
                System.out.println("YES");
            }
        }
        scanner.close();
    }

    private static boolean isSuspicious(String tasks) {
        HashSet<Character> completedTasks = new HashSet<>();
        char lastTask = '\0'; // Initialize with null character

        for (char task : tasks.toCharArray()) {
            if (task != lastTask) {
                if (completedTasks.contains(task)) {
                    return true; // Found a suspicious task switch
                }
                completedTasks.add(task);
                lastTask = task;
            }
        }
        return false; // No suspicious behavior detected
    }
}

//A. Maximum GCD
//https://codeforces.com/problemset/problem/1370/A
import java.util.Scanner;

public class MaximumGCD {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int t = scanner.nextInt(); 
        
        for (int i = 0; i < t; i++) {
            int n = scanner.nextInt();
            // The maximum GCD is simply n / 2
            System.out.println(n / 2);
        }
        
        scanner.close();
    }
}

//A. Plus One on the Subset
//https://codeforces.com/problemset/problem/1624/A
import java.util.Scanner;

public class PlusOneOnTheSubset {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int t = scanner.nextInt(); 
        
        for (int i = 0; i < t; i++) {
            int n = scanner.nextInt();
            int[] a = new int[n];
            
          
            for (int j = 0; j < n; j++) {
                a[j] = scanner.nextInt();
            }
            
            // Find maximum element in the array using a standard for loop
            int max_a = a[0]; 
            for (int j = 1; j < n; j++) {
                if (a[j] > max_a) {
                    max_a = a[j]; 
                }
            }
            
            // Calculate total operations needed to make all elements equal to max_a
            long operations = 0;
            for (int j = 0; j < n; j++) {
                operations += (max_a - a[j]); // Sum of differences
            }
            
            System.out.println(operations); 
        }
        
        scanner.close();
    }
}

// 9. Palindrome Number
// https://leetcode.com/problems/palindrome-number/?envType=study-plan-v2&envId=top-interview-150
class Solution {
    public boolean isPalindrome(int x) {
         if (x < 0 || (x % 10 == 0 && x != 0)) {
            return false;
        }

        int reversedHalf = 0;
        // Step 2: Reverse the second half of the number
        while (x > reversedHalf) {
            reversedHalf = reversedHalf * 10 + x % 10; 
            x /= 10; 
        }

       
        return x == reversedHalf || x == reversedHalf / 10; 
    }
        
}