class Solution {
public:
vector<int> nextGreaterElement(vector<int>& nums1, vector<int>& nums2) {
vector<int>greater=nextGreaterElement(nums2);
unordered_map<int,int>greaterMap;
for(int i=0;i<nums2.size();i++){
greaterMap[nums2[i]]=greater[i];
}
vector<int>res(nums1.size());
for(int i=0;i<nums1.size();i++){
res[i]=greaterMap[nums1[i]];
}
return res;
}
vector<int> nextGreaterElement(vector<int>& nums){
int n=nums.size();
vector<int>res(n);
stack<int> s;
for(int i=n-1;i>=0;i--){
while(!s.empty()&&s.top()<=nums[i]){
s.pop();
}
res[i]=s.empty()?-1:s.top();
s.push(nums[i]);
}
return res;
}
};