C++40分求助

#include<bits/stdc++.h>
int main(){
	int n,a[105];
	scanf("%d",&n);
	for(int i=n;i>=0;i--) 
		scanf("%d",&a[i]);
	for(int i=n;i>=1;i--){
		if(a[i]==0){continue;}
		else if(a[i]==-1) printf("-x^%d",i);
		else if(a[i]==1 && i!=n){printf("+x^%d",i);
		} 
		else if(a[i]==1 && i==n){printf("x^%d",i);} 
		else{
			if(a[i]>0) printf("+%dx^%d",a[i],i);
			else printf("%dx^%d",a[i],i);
		}
	}
	if(a[0]!=0){
		if(a[0]>0) printf("+");
		printf("%d",a[0]);
		
	}
	return 0;
}