3 WA 4 WA 其他AC

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int xiShu = sc.nextInt();
        StringBuilder builder = new StringBuilder();
        for (int i = xiShu; i >= 0; i--) {
            int xi = sc.nextInt();
            if(xi>0 && i!=xiShu){
                builder.append("+");
            }
            if(xi<0){
                builder.append("-");
            }
            if(i==0){
                builder.append(Math.abs(xi));
            }
            if(Math.abs(xi)>1 && i!=0 && i!=1){
                builder.append(Math.abs(xi)).append("x^").append(i);
            }
            if(Math.abs(xi)==1 && i!=0 && i!=1){
                builder.append("x^").append(i);
            }
            if(Math.abs(xi)>1 && i==1){
                builder.append(Math.abs(xi)).append("x");
            }
        }
        System.out.print(builder);
    }
}