README_EN.md

1507. Reformat Date

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Description

Given a date string in the form Day Month Year, where:

• Day is in the set {"1st", "2nd", "3rd", "4th", ..., "30th", "31st"}.
• Month is in the set {"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"}.
• Year is in the range [1900, 2100].

Convert the date string to the format YYYY-MM-DD, where:

• YYYY denotes the 4 digit year.
• MM denotes the 2 digit month.
• DD denotes the 2 digit day.

 

Example 1:

Input: date = "20th Oct 2052"
Output: "2052-10-20"

Example 2:

Input: date = "6th Jun 1933"
Output: "1933-06-06"

Example 3:

Input: date = "26th May 1960"
Output: "1960-05-26"

 

Constraints:

• The given dates are guaranteed to be valid, so no error handling is necessary.

Solutions

Python3

class Solution:
    def reformatDate(self, date: str) -> str:
        months = ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"]
        mapper = {v: str(k + 1) for k, v in enumerate(months)}
        split = date.split(' ')
        year = split[2]
        month = mapper.get(split[1])
        day = split[0][:len(split[0]) - 2]
        return year + '-' + month.zfill(2) + '-' + day.zfill(2)

Java

class Solution {
    public String reformatDate(String date) {
        Map<String, Integer> mapper = new HashMap<>();
        String[] months = {"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
        for (int i = 0; i < months.length; ++i) {
            mapper.put(months[i], i + 1);
        }
        String[] split = date.split(" ");
        int year = Integer.parseInt(split[2]);
        int month = mapper.get(split[1]);
        int day = Integer.parseInt(split[0].substring(0, split[0].length() -2));
        return String.format("%d-%02d-%02d", year, month, day);
    }
}

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