城墙防线

/*
 * Problem Statement:
 * Given an array of intervals representing ramparts, each rampart can expand to the left, right, or both directions.
 * The goal is to determine the maximum expansion value such that no ramparts overlap after expansion.
 * Initial intervals are non-overlapping and sorted in ascending order.
 */

import java.util.Arrays;

public class RampartExpansionStream {
    public int maxExpansion(int[][] rampart) {
        int left = 0, right = Integer.MAX_VALUE;
        while (left < right) {
            int mid = (left + right + 1) / 2;
            if (canExpand(rampart, mid)) {
                left = mid;
            } else {
                right = mid - 1;
            }
        }
        return left;
    }

    private boolean canExpand(int[][] rampart, int length) {
        return Arrays.stream(rampart, 1, rampart.length)
                     .allMatch(interval -> interval[0] - rampart[Arrays.asList(rampart).indexOf(interval) - 1][1] >= 2 * length);
    }

    public static void main(String[] args) {
        RampartExpansionStream res = new RampartExpansionStream();
        int[][] rampart1 = {{0, 3}, {4, 5}, {7, 9}};
        int[][] rampart2 = {{1, 2}, {5, 8}, {11, 15}, {18, 25}};
        System.out.println(res.maxExpansion(rampart1)); // Output: 3
        System.out.println(res.maxExpansion(rampart2)); // Output: 4
    }
}