题解 | 牛的生长情况

1. 单调栈。

import java.util.*;


public class Solution {
    public int[] weightGrowth (int[] weights) {
        final int n = weights.length;
        int[] ans = new int[n];
        Deque<Integer> stack = new ArrayDeque<>();
        for (int i = 0; i < n; ++i) {
            while (!stack.isEmpty() && weights[i] > weights[stack.getLast()]) {
                final int idx = stack.removeLast();
                ans[idx] = i - idx;
            }
            stack.addLast(i);
        }
        while (!stack.isEmpty()) {
            ans[stack.removeLast()] = -1;
        }
        return ans;
    }
}