leetcode1507 Reformat Date

题目：

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.

字符串操作：sscanf，s.c_str() , sprintf

代码如下：

class Solution {
public:string reformatDate(string date) {int year,imon,day;char month[4];sscanf(date.c_str(),"%d%*s %s %d",&day,month,&year);vector<string> smon = {"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};for(int i = 0; i < smon.size();i++){if(smon[i] == month){imon = i + 1;break;}}char res[20];sprintf(res,"%04d-%02d-%02d",year,imon,day);return res;}
};