Sept lunchtime div 2 PAIRSUM2

this code gives TLE for subtask 2. please help me how this is happening and how i can avoid these`package sept_Lunchtime;

import java.util.*;

public class pairSum2 {

public static void main(String[] args) {

	Scanner sc = new Scanner(System.in);

	int t = sc.nextInt();
	while (t-- > 0) {

		int n = sc.nextInt();
		int quer = sc.nextInt();
		int b[] = new int[n];
		for (int i = 1; i <= n - 1; i++)
			b[i] = sc.nextInt();

		for (int i = 1; i <= quer; i++) {
			int p=0, q=0;
			if (sc.hasNext()) {
				p = sc.nextInt();
				q = sc.nextInt();
			}

			int x = Integer.max(p, q);
			int y = Integer.min(p, q);

			if ((x - y) % 2 == 0) { // odd difference
				System.out.println("UNKNOWN");

			} else {
				long sum = 0;
				int sign = 0;
				for (int k = x - 1; k >= y; k--) {
					if (sign % 2 == 0)
						sum = sum + b[k];
					else
						sum = sum - b[k];

					sign++;
					// System.out.print(sum + " ");
				}

				System.out.println(sum);
			}

		}
	}

}

}
`

Try to optimize the snippet by pre processing your data.

You Time Complexity - O (N * Q)
Go for linear time. Think!

just preprocess it as u do it in prefix sum


Hope this helps :slightly_smiling_face: