Day 119.java

class Solution {
    public int maxPeople(int[] arr) {
        int n = arr.length;
        int[] left = new int[n];
        int[] right = new int[n];
        Stack<Integer> st = new Stack<>();

        for (int i = 0; i < n; i++) {
            while (!st.isEmpty() && arr[st.peek()] < arr[i]) {
                st.pop();
            }
            left[i] = st.isEmpty() ? -1 : st.peek();
            st.push(i);
        }

        st.clear();

        for (int i = n - 1; i >= 0; i--) {
            while (!st.isEmpty() && arr[st.peek()] < arr[i]) {
                st.pop();
            }
            right[i] = st.isEmpty() ? n : st.peek();
            st.push(i);
        }

        int ans = 0;
        for (int i = 0; i < n; i++) {
            int visible = (i - left[i] - 1) + (right[i] - i - 1) + 1;
            ans = Math.max(ans, visible);
        }

        return ans;
    }
}