转变日期格式Java

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# 题目

给你一个字符串 date ，它的格式为 Day Month Year ，其中：

Day 是集合 {"1st", "2nd", "3rd", "4th", ..., "30th", "31st"} 中的一个元素。
Month 是集合 {"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"} 中的一个元素。
Year 的范围在 [1900, 2100] 之间。请你将字符串转变为 YYYY-MM-DD 的格式，其中：
YYYY 表示 4 位的年份。
MM 表示 2 位的月份。
DD 表示 2 位的天数。

示例 1：

输入：date = "20th Oct 2052"
输出："2052-10-20"

示例 2：

输入：date = "6th Jun 1933"
输出："1933-06-06"

示例 3：

输入：date = "26th May 1960"
输出："1960-05-26"

提示：

给定日期保证是合法的，所以不需要处理异常输入。

# 思路

字典表

# 解法

class Solution {

    private final List<String> days = Arrays.asList(
            "1st", "2nd", "3rd", "4th", "5th", "6th", "7th", "8th", "9th", "10th",
            "11th", "12th", "13th", "14th", "15th", "16th", "17th", "18th", "19th",
            "20th", "21st", "22nd", "23rd", "24th", "25th", "26th", "27th", "28th",
            "29th", "30th", "31st"
    );

    private final List<String> months = Arrays.asList(
            "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
    );

    public String reformatDate(String date) {
        String[] dates = date.split(" ");
        String year = dates[2];
        int month = months.indexOf(dates[1]) + 1;
        int day = days.indexOf(dates[0]) + 1;
        return String.format("%s-%02d-%02d", year, month, day);
    }

    public static void main(String[] args) {
        Solution s = new Solution();
        List<String> testDataList = Arrays.asList(
                "20th Oct 2052",
                "6th Jun 1933",
                "26th May 1960"
        );
        testDataList.forEach(date ->
                System.out.println(s.reformatDate(date))
        );
    }
}

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# 总结

分析出几种情况，然后分别对各个情况实现

#Java