package question;

import java.util.HashMap;
import java.util.Stack;

/*
 @author: Roderland
 @create: 2020年08月18日---14:05
*/
public class Question496 {
 public int[] nextGreaterElement(int[] nums1, int[] nums2) {
 int[] array = new int[nums1.length];
 int[] index = new int[nums1.length];
 for (int i = 0; i < nums1.length; i++) {
 for (int j = 0; j < nums2.length; j++) {
 if (nums2[j]==nums1[i]) {
 index[i]=j;
 break;
 }
 }
 }
 for (int i = 0; i < nums1.length; i++) {
 boolean flag = false;
 for (int j = index[i]+1; j < nums2.length; j++) {
 if (nums2[j]>nums1[i]) {
 flag=true;
 array[i]=nums2[j];
 break;
 }
 }
 if (!flag) array[i]=-1;
 }
 return array;
 }

 //solution2
 public static void main(String[] args) {
 //nums1 = [4,1,2], nums2 = [1,3,4,2].
 int[] nums1 = new int[]{4,1,2};
 int[] nums2 = new int[]{1,3,4,2};
 new Question496().nextGreaterElement2(nums1, nums2);
 }
 public int[] nextGreaterElement2(int[] nums1, int[] nums2) {
 int[] array = new int[nums1.length];
 Stack<Integer> stack = new Stack<>();
 HashMap<Integer, Integer> hashMap = new HashMap<>();
 for (int i = 0; i < nums2.length; i++) {
 while (!stack.isEmpty()&&nums2[i]>stack.peek()) {
 hashMap.put(stack.pop(), nums2[i]);
 }
 stack.push(nums2[i]);
 }
 while (!stack.isEmpty()) {
 hashMap.put(stack.pop(), -1);
 }
 for (int i = 0; i < nums1.length; i++) {
 array[i] = hashMap.get(nums1[i]);
 }
 return array;
 }
}