题解

#include <bits/stdc++.h>
using namespace std;

int n;
int num;


int main(){
    cin>>n;
    int cnt=n;
    while(cnt>=0){
        cin>>num;
        if(num!=0){
            if(cnt!=n) if(num>0) cout<<"+";
            if(num<0) cout<<"-";
            if(abs(num)!=1 || cnt==0) cout<<abs(num);
            if(cnt>0) cout<<"x";
            if(cnt>1) cout<<"^"<<cnt;
        }
        cnt--;
    }
    return 0;
}