洛谷 P1067 [NOIP2009 普及组] 多项式输出 Python题解

n = int(input())
lst = list(map(int, input().split()))
strr = ''
for i in range(len(lst)):
    if i == len(lst) - 1:
        break
    if lst[i] > 1:  # 大于1就要写上前面呗
        if n == 1:
            strr += str(lst[i]) + "x+"
        else:
            strr += str(lst[i]) + "x^%d+" % n
    elif lst[i] == 1:  # 等于1的时候前面不就不写
        if n == 1:
            strr += "x+"
        else:
            strr += "x^%d+" % n
    elif lst[i] < -1:
        if n == 1:  # 多一个加号 就得删了
            strr = strr[:-1]
            strr += str(lst[i]) + "x+"
        else:
            strr = strr[:-1]
            strr += str(lst[i]) + "x^%d+" % n
    elif lst[i] == -1:
        if n == 1:
            strr = strr[:-1]
            strr += "-x+"
        else:
            strr = strr[:-1]
            strr += "-x^%d+" % n
    else:
        strr += ''  # 要是0不就是不写吗
    n -= 1  # 每次减一不就是次方吗

if lst[-1] == 0:  # 处理最后一个
    print(strr[:-1])
if lst[-1] > 0:
    strr += str(lst[-1])
    print(strr)
if lst[-1] < 0:
    strr = strr[:-1]
    strr += str(lst[-1])
    print(strr)