Question

我正在研究项目欧拉问题19的解决方案

目标是找到20世纪第一个月的星期日数量。我试图仅使用循环（不使用日期时间）来完成问题。

这是我现在的代码：

days  = []

yearCnt = 1900;
dayCnt = 1;

Jan = 31;
Mar = 31;
Apr = 30;
May = 31;
Jun = 30;
Jul = 31;
Aug = 31;
Sep = 30;
Oct = 31;
Nov = 30;
Dec = 31;

while yearCnt < 2001:
    if yearCnt == 1900:
        Feb = 28;
    elif yearCnt%4 == 0:
        Feb = 29;
    else:
        Feb = 28;
    days.append(1);
    while dayCnt < Jan:
        days.append(0);
        dayCnt += 1;
    dayCnt = 1;
    days.append(1);
    while dayCnt < Feb:
        days.append(0);
        dayCnt += 1;
    dayCnt = 1;
    days.append(1);
    while dayCnt < Mar:
        days.append(0);
        dayCnt += 1;
    dayCnt = 1;
    days.append(1);
    while dayCnt < Apr:
        days.append(0);
        dayCnt += 1;
    dayCnt = 1;
    days.append(1);
    while dayCnt < May:
        days.append(0);
        dayCnt += 1;
    dayCnt = 1;
    days.append(1);
    while dayCnt < Jun:
        days.append(0);
        dayCnt += 1;
    dayCnt = 1;
    days.append(1);
    while dayCnt < Jul:
        days.append(0);
        dayCnt += 1;
    dayCnt = 1;
    days.append(1);
    while dayCnt < Aug:
        days.append(0);
        dayCnt += 1;
    dayCnt = 1;
    days.append(1);
    while dayCnt < Sep:
        days.append(0);
        dayCnt += 1;
    dayCnt = 1;
    days.append(1);
    while dayCnt < Oct:
        days.append(0);
        dayCnt += 1;
    dayCnt = 1;
    days.append(1);
    while dayCnt < Nov:
        days.append(0);
        dayCnt += 1;
    dayCnt = 1;
    days.append(1);
    while dayCnt < Dec:
        days.append(0);
        dayCnt += 1;
    dayCnt = 1;
    yearCnt += 1;

sunCnt = 6;

while sunCnt <= len(days):
    days[sunCnt] += 1;
    sunCnt += 7;

print(days.count(2));

我们的想法是创建一个包含所有日期的数组，其中第一个月的位置标记为1。然后另一个while循环遍历该数组并添加1以标记所有星期日。从理论上讲，2的数量应该标志着月初的星期日数量。

它目前给出答案173.我知道答案是171但我想知道我哪里出错了。

Answer 1

如果您将代码更改为在1901年1月1日开始计数，则它可以工作。您只需要在标记每个星期日的末尾更改循环。

sunCnt = 6;
# Skip the year 1900
# Adding 364 will get to 1901 without messing up the day of the week
sunCnt += 364;

while sunCnt <= len(days):
    days[sunCnt] += 1;
    sunCnt += 7;

Python while while循环在本月的第一天找到星期日

1 个答案: