救救我

#include <bits/stdc++.h>

using namespace std;

long long n , a;

int main( ) {
	cin >> n;
	
	for (int i = n ; i >= 0 ; i--) {
		cin >> a;
		
		if (a == 0) {
			continue;
		}
		
		if (i == 0) {
			if (a > 0 && n != 0) {
				cout << "+";
			}
			cout << a;
			continue;
		}
		
		if (a > 0 && i != n) {
			cout << "+";
		}
		
		if (a != 1 && a != -1) {
			cout << a;
		} else if (a == -1){
			cout << "-1"; 
		}
		
		if (i == 1) {
			cout << "x";
		} else {
			cout << "x^" << i;
		}
	}
}

为什么错了