Calculates the difference in the number of days between two dates C++/java

1--java

Parsing: Calling the Calendar class in Java

intnew  calendar.getinstance ();　　Cal.settime (date1);　　 int time1 = cal.get (calendar.day_of_year);　　Cal.settime (DATE2);　　 int time2 = cal.get (calendar.day_of_year);  //long days = Math.Abs (time1-time2)/(24*3600*1000); return Math.Abs (day1-day2);}　　

2--java

int　　Days (Date date1,date date2) {  long time1 = Math.Abs (Date1.gettime ()-date2.gettime ());  return (int) time1/(24*3600*1000);}

Analysis: First of all to know about the concept of leap year, every four years a run, 400 years run, and can not be divisible by 100. Because, leap year February has 29 days, a total of 366 days.

Pseudocode: First the date string of the year, month, day separate, type YYYY-MM-DD, get two dates, year1,month1,day1,year2,month2,day2

If the year, the month is the same:

return day1-day2; (large decrease)

If the year is the same, the months are different:

Calculate date1, how many days in the year d1;date2, how many days of the year D2

return d1-d2;

If the year is different:

D1=date1 is the number of days of the year

D2=date2 How many days before the end of the year

d3= the number of days between the two year difference

Return d1+d2+d

#include <iostream>using namespace std; PublicBOOL Stringtodate (string date,int&year,int&month,int&Day ) { Year= Atoi (Date.substr (0,4). C_STR ()); Month=atio (Date.substr (5,2). C_STR ()); Day=atio (Date.substr (8,2). C_STR ()); day[12]={31,29,31,30,31,30,31,31,30,31,30,31}; if(Islear (year)) day[1]=29; returnYear>0&&month>0&&month<=12&&day<=day[month-1];} PublicBOOL Isleap (intYear ) {return((year%4==0) | | (year%400==0)) && (year&100!=0);} Public intDaysinyear (intYearintMonth,intDay ) {intDays =Day ; intDay[12]={31,28,31,30,31,30,31,31,30,31,30,31}; if(Isleap (year)) day[1]=29;  for(inti=0;i<month-1;i++) { days+=Day[i]; }returnDays ;} Publicbetween_days (String date1,string date2) {if(Stringtodate (Date1,int&AMP;YEAR1,int&month1,int&day1) &&stringtodate (String date2,int&AMP;YEAR2,int&month2,int&day2)) {if(year1==year2&&month1==month2) {returnday1>day2?day1-day2:day2-Day1; }Else if(year1==year2) {intD1 =daysinyear (year1,month1,day1); intD2 =daysinyear (year2,month2,day2); returnd1>d2?d1-d2:d2-D1; }Else{if(year1<year2)　　　　　　{swap (YEAR1,YEAR2);　　　　　　Swap (MONTH1,MONTH2);　　　　Swap (DAY1,DAY2); }intD1=0;  for(intj=year2+1;j<year1;j++) {if(Isleap (j)) D1+=366; ElseD1+=365; }intD2=daysinyear (year1,month1,day1); if(Isleap (year2)) D2=d2+366-daysinyear (year2,month2,day2); ElseD2=d2+365-daysinyear (year2,month2,day2); returnd1+D2; }}}

　　　　　　

　　　　

　　　　　　

Calculates the difference in the number of days between two dates C++/java