class Solution {
    public boolean canReach(int[] arr, int start) {
        int n = arr.length;
        boolean visited[] = new boolean[n];
        Queue<Integer> queue = new LinkedList<>();
        queue.offer(start);
        while (!queue.isEmpty()) {
            int current = queue.poll();
            if (arr[current] == 0) {
                return true;
            }
            int left = current - arr[current];
            int right = current + arr[current];
            if (left >= 0 && !visited[left]) {
                visited[left] = true;
                queue.offer(left);
            }
            if (right < n && !visited[right]) {
                visited[right] = true;
                queue.offer(right);
            }
        }
        return false;
    }
}

/*
    arr = [4,2,3,0,3,1,2], start = 5

    queue.offer(5)

    {
        current = 5
        arr[5] -> 1
        left = 5 - 1 = 4
        right = 5 + 1 = 6

        visited[4] = true
        queue.offer(4)

        visited[6] = true
        queue.offer(6)

        // queue   = [4, 6]
        // visited = [0, 0, 0, 0, 1, 1, 1]
    }
    {
        current = 4
        arr[4] -> 3
        left = 4 - 3 = 1
        right = 4 + 3 = 7

        visited[1] = true
        queue.offer(1)

        // queue = [6, 1]
        // visited = [0, 1, 0, 0, 1, 1, 1]
    }
    {
        current = 6
        arr[6] -> 2
        left = 6 - 2 = 4
        right = 6 + 2 = 8

        // queue = [1]
        // visited = [0, 1, 0, 0, 1, 1, 1]
    }
    {
        current = 1
        arr[1] -> 2
        left = 1 - 2 = -1
        right = 1 + 2 = 3

        visited[3] = true
        queue.offer(3)

        // queue = [3]
        // visited = [0, 1, 0, 1, 1, 1, 1]
    }
    {
        current = 3
        arr[1] -> 0
        return true
    }
*/