题解 | 多项式输出

n = int(input())
l = input().split()
s = ''
for i in range(n,0,-1):
    if int(l[n-i]) == -1:
        if int(i) != 1:
            d = '-x^'+str(i)
        else:
            d = '-x'
    elif int(l[n-i]) == 1 and n - i != 0:
        if int(i) != 1:
            d = '+x^'+str(i)
        else:
            d = '+x'
    elif int(l[n-i]) == 1 and n - i == 0:
        if int(i) != 1:
            d = 'x^'+str(i)
        else:
            d = 'x'
    else:
        if int(l[n - i]) >= 0 and n - i != 0:
            if int(i) != 1:
                d = '+'+l[n - i]+'x^'+str(i)
            else:
                d = '+'+l[n - i]+'x'
        else:
            if int(i) != 1:
                d = l[n - i]+'x^'+str(i)
            else:
                d = l[n - i]+'x'
    if int(l[n-i]) != 0:
        s = s + d
if int(l[n]) > 0:
    s = s + '+' + l[n]
elif int(l[n]) < 0:
    s = s + l[n]
print(s)