竟然全部$\colorbox{red}{\color{white}WA}$了！！！为各位大佬献上代码：

#include"stdio.h"
#include"string.h"
int main(void){
    int n,a[101];
    char ans[1000]="";
    scanf("%d",&n);
    for(int i=0;i<=n;i++)
        scanf("%d",&a[i]);
    for(int i=n;i>=0;i--)
        if(a[i]){
            if(a[i]==1){
                if(i==0)
                    sprintf(ans,"+1");
                else if(i==1)
                    sprintf(ans,"+x");
                else
                    sprintf(ans,"+x^%d",i);
            }else if(a[i]==-1){
                if(i==0)
                    sprintf(ans,"-1");
                else if(i==1)
                    sprintf(ans,"-x");
                else
                    sprintf(ans,"-x^%d",i);
            }else{
                if(i==0){
                    if(a[i]>=0)
                        sprintf(ans,"+");
                    sprintf(ans,"%d",a[i]);
                }else if(i==1){
                    if(a[i]>=0)
                        sprintf(ans,"+");
                    sprintf(ans,"%dx",a[i]);
                }else{
                    if(a[i]>=0)
                        sprintf(ans,"+");
                    sprintf(ans,"%dx^%d",a[i],i);
                }
            }
        }
    const bool flag=(ans[0]=='+');
    for(int i=flag;i<strlen(ans);i++)
        printf("%c",ans[i]);
    return 0;
}