Solution.java

class Solution {
    public int[] findMaximums(int[] nums) {
        int n = nums.length;
        int[] left = new int[n];
        int[] right = new int[n];
        Arrays.fill(left, -1);
        Arrays.fill(right, n);
        Deque<Integer> stk = new ArrayDeque<>();
        for (int i = 0; i < n; ++i) {
            while (!stk.isEmpty() && nums[stk.peek()] >= nums[i]) {
                stk.pop();
            }
            if (!stk.isEmpty()) {
                left[i] = stk.peek();
            }
            stk.push(i);
        }
        stk.clear();
        for (int i = n - 1; i >= 0; --i) {
            while (!stk.isEmpty() && nums[stk.peek()] >= nums[i]) {
                stk.pop();
            }
            if (!stk.isEmpty()) {
                right[i] = stk.peek();
            }
            stk.push(i);
        }
        int[] ans = new int[n];
        for (int i = 0; i < n; ++i) {
            int m = right[i] - left[i] - 1;
            ans[m - 1] = Math.max(ans[m - 1], nums[i]);
        }
        for (int i = n - 2; i >= 0; --i) {
            ans[i] = Math.max(ans[i], ans[i + 1]);
        }
        return ans;
    }
}