找朋友（华为OD D卷）

#include <iostream>
#include <stack>
#include <vector>

using namespace std;

struct student{
    int height;
    int idx;
    student(){}
    student(int h,int i):height(h),idx(i){}
};

int main(){
    int n;
    while (cin>>n){
        vector<student> sV(n);
        int h;
        stack<student> hS;
        vector<int> ans(n,0);
        for (int i = 0; i < n; ++i) {
            cin>>h;
            sV.emplace_back(h,i);
            while (!hS.empty() && hS.top().height < h){
                student stu = hS.top();
                ans[stu.idx] = i;
                hS.pop();
            }
            hS.emplace(h,i);
        }
        for (int a:ans) {
            cout<<a<<" ";
        }
        cout<<endl;
    }

    return 0;
}