题解

代码见下：

#include<stdio.h>
#include<malloc.h>
FILE *o;
FILE *i;
int main(){
    unsigned long long n,i1,*s;
    scanf("%llu",&n);
//    s=(long long*)malloc(n*sizeof(s[0]));
    long long x=0,out=1;
    for(i1=n;i1>1&&out;i1--){
        scanf("%lld",&x);
        if(x==0)continue;
        if(x==1){
            printf("x^%lld",i1);
        }else if(x==-1){
            printf("-x^%lld",i1);
        }else printf("%lldx^%lld",x,i1);
        out=0;
    }
    for(;i1>1;i1--){
        scanf("%lld",&x);
        if(x==0)continue;
        if(x>0)printf("+");
        if(x==-1){
            printf("-x^%lld",i1);
            continue;
        }
        if(x==1){
            printf("x^%lld",i1);
            continue;
        }
        printf("%lldx^%llu",x,i1);
    }
    if(i1==1){
        scanf("%lld",&x);
        if(x){
            if(x>0)printf("+");
            if(x==1)printf("x");
            else if(x==-1)printf("-x");
            else printf("%lldx",x);
        }
        i1--;
    }
    if(i1==0){
        scanf("%lld",&x);
        if(x){
            if(x>0)printf("+");
            printf("%lld",x);
        }
    }
    if(out)printf("0");
    return 0;
}