81_Next_Greater_Element_I

class Solution:
    def nextGreaterElement(self, nums1: List[int], nums2: List[int]) -> List[int]:
        l=[]
        d=defaultdict(int)
        for i in range(len(nums2)):
            if not l:
                l.append(nums2[i])
                continue
            if l[len(l)-1]<nums2[i]:
                while l and l[len(l)-1]<nums2[i]:
                    d[l[len(l)-1]]=nums2[i]
                    l=l[:-1]
            l.append(nums2[i])
        ans=[]
        for t in nums1:
            if d[t]:
                ans.append(d[t])
            else:
                ans.append(-1)
        return ans