求助 P1067
60分

#include<bits/stdc++.h>
#define int long long
#define endl '\n'
using namespace std;
const int N = 1e5+10;
signed main(){
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	int n;
	cin>>n;
	int fr[n+1];
	for(int i=0;i<=n;i++){
		cin>>fr[i];
	}
	if(fr[0]>0&&fr[0]!=1){
		printf("%dx^%d",fr[0],n);
	} 
	if(fr[0]<0&&fr[0]!=-1){
		printf("%dx^%d",fr[0],n);
	}
	if(fr[0]==1){
		printf("x^%d",fr[0],n);
	}
	if(fr[0]==-1){
		printf("-x^%d",fr[0],n);	
	}
	for(int i=1;i<=n-2;i++){
		if(fr[i]==1){
			printf("+x^%d",n-i);
			continue;
		}
		if(fr[i]==-1){
			printf("-x^%d",n-i);
			continue;
		}
		if(fr[i]==0){
			continue;
		}
		if(fr[i]<0){
			printf("%dx^%d",fr[i],n-i);
			continue;
		}
		if(fr[i]>0){
			printf("+%dx^%d",fr[i],n-i);
			continue;
		}
	}
	if(fr[n-1]<0){
		printf("%dx",fr[n-1]);
	}
	if(fr[n-1]>0){
		printf("+%dx",fr[n-1]);
	}
	if(fr[n]<0){
		printf("%d",fr[n]);
	}
	if(fr[n]>0){
		printf("+%d",fr[n]);
	}
	return 0;
}