Untitled

import java.util.*;

public class SystemVulnerabilityCalculator {

    public static int getSystemVulnerabilitySum(List<Integer> vulnerability) {
        int n = vulnerability.size();
        long sum = 0;
        final int MOD = 1000000007;

        int[] leftExtent = new int[n];
        int[] rightExtent = new int[n];
        
        Stack<Integer> stack = new Stack<>();

        // Calculating left extent for each position
        for (int i = 0; i < n; i++) {
            while (!stack.isEmpty() && vulnerability.get(stack.peek()) < vulnerability.get(i)) {
                stack.pop();
            }
            leftExtent[i] = stack.isEmpty() ? i + 1 : i - stack.peek();
            stack.push(i);
        }

        // Clear the stack for right extent calculation
        stack.clear();

        // Calculating right extent for each position
        for (int i = n - 1; i >= 0; i--) {
            while (!stack.isEmpty() && vulnerability.get(stack.peek()) <= vulnerability.get(i)) {
                stack.pop();
            }
            rightExtent[i] = stack.isEmpty() ? n - i : stack.peek() - i;
            stack.push(i);
        }

        // Compute contributions of each index
        for (int i = 0; i < n; i++) {
            long totalSegments = (long) leftExtent[i] * rightExtent[i];
            long contribution = (long) vulnerability.get(i) * totalSegments;
            sum = (sum + contribution) % MOD;
        }

        return (int) sum;
    }

    public static void main(String[] args) {
        List<Integer> vulnerability = Arrays.asList(4, 2, 1, 2);
        System.out.println("Total System Vulnerability Sum: " + getSystemVulnerabilitySum(vulnerability));
        // Expected output: 59
    }
}