A4.多项式求值

#include<iostream>
#include<cmath>
using namespace std;
int main(){
    int n;
    cin>>n;
    for(int i=n;i>=0;i--){
        int x;
        cin>>x;
        if(x==0) continue;
        if(x>0&&i!=n) cout<<"+";
        if(i==0||abs(x)>1) cout<<x;
        if(x==-1&&i!=0) cout<<"-"; 
        if(i!=0) cout<<"x";
        if(i>1) cout<<"^"<<i;
    }
    return 0;
}