739. 每日温度 - 力扣（LeetCode）

class Solution {
    public int[] dailyTemperatures(int[] temperatures) {
        int[] result = new int[temperatures.length];
        Deque<Integer> monoStack = new LinkedList<Integer>();
        
        for(int i=0;i<temperatures.length;i++){
            if(monoStack.isEmpty()){
                monoStack.push(i);
                continue;
            }
            
            if(temperatures[i] <= temperatures[monoStack.peek()]){
                monoStack.push(i);
            }else{
                while (!monoStack.isEmpty() && temperatures[i] > temperatures[monoStack.peek()]){
                    Integer pop = monoStack.pop();
                    result[pop] = i-pop;
                }
                 monoStack.push(i);
            }
        }
        
        return result;
    }
}

496. 下一个更大元素 I - 力扣（LeetCode） 

class Solution {
    public int[] nextGreaterElement(int[] nums1, int[] nums2) {
        int[] temp = new int[nums2.length];
        Arrays.fill(temp,-1);

        Deque<Integer> monoStack = new LinkedList<>();
        HashMap<Integer,Integer> nums2Map = new HashMap<>();
        for(int i=0;i<nums2.length;i++){
            nums2Map.put(nums2[i],i);
            if(monoStack.isEmpty()){
                monoStack.push(i);
                continue;
            }
            
            if(nums2[i] <= nums2[monoStack.peek()]){
                monoStack.push(i);
            }else{
                while (!monoStack.isEmpty() && nums2[i] > nums2[monoStack.peek()]){
                    Integer pop = monoStack.pop();
                    temp[pop] = nums2[i];
                }
                monoStack.push(i);
            }
        }
        
        int[] result = new int[nums1.length];
        for(int i=0;i<nums1.length;i++){
            Integer index = nums2Map.get(nums1[i]);
            result[i] = temp[index];
        }

        return result;
    }
}

 503. 下一个更大元素 II - 力扣（LeetCode）

class Solution {
    public int[] nextGreaterElements(int[] nums) {
        int[] nums2 = new int[nums.length*2];
        for(int i=0;i<nums.length;i++){
            nums2[i] = nums[i];
            nums2[i+nums.length] = nums[i];
        }
        
        int[] temp = new int[nums.length*2];
        Arrays.fill(temp,-1);
        Deque<Integer> monoStack = new LinkedList<>();
        for(int i=0;i<nums2.length;i++){
            if(monoStack.isEmpty()){
                monoStack.push(i);
                continue;
            }
            
            if(nums2[i] < nums2[monoStack.peek()]){
                monoStack.push(i);
            }else{
                while (!monoStack.isEmpty() && nums2[i] > nums2[monoStack.peek()]){
                    Integer pop = monoStack.pop();
                    temp[pop] = nums2[i];
                }
                monoStack.push(i);
            }
        }

        int[] result = new int[nums.length];
        for(int i=0;i<nums.length;i++){
            result[i] = temp[i];
        }
        
        return result;
    }
}