PAT 甲级 1002 题目：为什么代码跑不过测试点 1？

Question

# -*- coding:utf-8 -*-
from collections import deque


def read_polynomial():
    tokens = input().split(' ')[1:]
    p = deque([])
    for i in range(0, len(tokens) - 1, 2):
        p.append((int(tokens[i]), float(tokens[i+1])))
    return p


def add_polynomial(p1: deque, p2: deque):
    ret = deque([])
    while len(p1) != 0 and len(p2) != 0:
        item1 = p1[0]
        item2 = p2[0]
        if item1[0] == item2[0]:
            coef = item1[1] + item2[1]
            if coef != 0.0:
                ret.append((item1[0], coef))
            p1.popleft()
            p2.popleft()
        elif item1[0] > item2[1]:
            ret.append(p1.popleft())
        else:
            ret.append(p2.popleft())

    if len(p1) != 0:
        ret.extend(p1)

    if len(p2) != 0:
        ret.extend(p2)

    return ret


def print_polynomial(p: deque):
    ret = [str(len(p))]
    while len(p) != 0:
        item = p.popleft()
        ret.append(str(int(item[0])))
        ret.append(f'{item[1]:.1f}')
    print(' '.join(ret))


if __name__ == '__main__':
    p1 = read_polynomial()
    p2 = read_polynomial()

    p3 = add_polynomial(p1, p2)
    print_polynomial(p3)