题解

#include <iostream>
using namespace std;

int main() {
    int n;
    int num;
    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;
}