Next Greater Element II

 https://leetcode.com/problems/next-greater-element-ii/

vector<int> nextGreaterElements(vector<int>& nums) {
        int n=nums.size();//size
        vector<int>nqe(n,-1);//vector initialized with -1
        stack<int> s;
        for(int i=(2*n-1);i>=0;i--){ //to create a circular array and traverse from right to left
            while(!s.empty() && s.top()<=nums[i%n]) //if stack empty,(i%n because of circular array logic)
            {
                s.pop(); // we need to pop
            }
            if(i<n){
                if(!s.empty()){
                    nqe[i]=s.top();
                }
            }
            s.push(nums[i%n]);
        }
        return nqe;
    }