题目描述

blablabla

样例

blablabla

算法1

$O(n)$

Stack

时间复杂度

参考文献

Java 代码

class Solution {
    public boolean find132pattern(int[] nums) {
        if(nums.length < 3) return false;
        Stack<Integer> stack = new Stack<>();
        int second = Integer.MIN_VALUE;
        stack.push(nums[nums.length-1]);
        for(int i = nums.length-2;i>=0;i--){
            if(nums[i]< second){
                return true;
            }else{
                while(!stack.isEmpty() && stack.peek() < nums[i]){
                    second = stack.pop();
                }
                stack.push(nums[i]);
            }
        }
        return false;
    }
}