Create NGE.java

NGE.java

@@ -0,0 +1,22 @@
+//leetcode --> 496. Next Greater Element I
+import java.util.*;
+class Hactober {
+    public static int[] nextGreaterElement(int[] nums1, int[] nums2) {
+        HashMap<Integer,Integer> map = new HashMap<>();
+        Stack<Integer> s = new Stack<>();
+        for(int i:nums2){
+            while(!s.isEmpty()&&s.peek()<i)map.put(s.pop(),i);
+            s.push(i);
+        }
+        for(int i=0;i<nums1.length;i++){
+            nums1[i]=map.getOrDefault(nums1[i],-1);
+        }
+        return nums1;
+    }
+   public static void main(String[] args){
+        int[] arr1 = {4,1,2};
+        int[] arr2 = {1,3,4,2};
+        int[] res = nextGreaterElement(arr1,arr2);
+        for(int i : res)System.out.print(i + " ");
+   }
+}