1 files changed, 87 insertions, 0 deletions
diff --git a/challenge-187/mohammad-anwar/java/theweeklychallenge/DaysTogether.java b/challenge-187/mohammad-anwar/java/theweeklychallenge/DaysTogether.java
new file mode 100644
index 0000000000..0c0d0869fb
--- /dev/null
+++ b/challenge-187/mohammad-anwar/java/theweeklychallenge/DaysTogether.java
@@ -0,0 +1,87 @@
+package theweeklychallenge;
+
+/*
+
+Week 187:
+
+    https://theweeklychallenge.org/blog/perl-weekly-challenge-187
+
+Task #1: Days Together
+
+    Two friends, Foo and Bar gone on holidays seperately to the same
+    city. You are given their schedule i.e. start date and end date.
+
+    To keep the task simple, the date is in the form 'DD-MM' and all
+    dates belong to the  same calendar year i.e. between '01-01' and
+    '31-12'.
+
+    Also the year is non-leap year and both dates are inclusive.
+
+Compile and Run:
+
+    mohammad-anwar/java$ javac theweeklychallenge/DaysTogether.java
+    mohammad-anwar/java$ java  theweeklychallenge.DaysTogether
+
+*/
+
+import java.time.LocalDate;
+import java.time.temporal.ChronoUnit;
+import junit.framework.TestCase;
+import static junit.framework.Assert.*;
+
+public class DaysTogether extends TestCase {
+
+    public static void main(String[] args) {
+        junit.textui.TestRunner.run(
+            theweeklychallenge.DaysTogether.class
+        );
+    }
+
+    public void testDaysTogether() {
+        assertEquals(4, daysTogether("12-01","20-01","15-01","18-01"));
+        assertEquals(0, daysTogether("02-03","12-03","13-03","14-03"));
+        assertEquals(2, daysTogether("02-03","12-03","11-03","15-03"));
+        assertEquals(4, daysTogether("30-03","05-04","28-03","02-04"));
+    }
+
+    public static int daysTogether(
+        String sd1, String ed1, String sd2,    String ed2) {
+        LocalDate _sd1 = _date(sd1);
+        LocalDate _ed1 = _date(ed1);
+        LocalDate _sd2 = _date(sd2);
+        LocalDate _ed2 = _date(ed2);
+
+        int days = 0;
+
+        if (_ed1.compareTo(_sd2) < 0) {
+            return days;
+        }
+
+        if (_sd1.compareTo(_sd2) > 0) {
+            days = _daysTogether(_sd1, _ed1, _ed2);
+        }
+        else if (_ed2.compareTo(_sd2) > 0) {
+            days = _daysTogether(_sd2, _ed1, _ed2);
+        }
+
+        return days;
+    }
+
+    public static LocalDate _date(String dateStr) {
+        String[] splitDate = dateStr.split("-");
+        int day   = Integer.parseInt(splitDate[0]);
+        int month = Integer.parseInt(splitDate[1]);
+
+        return LocalDate.of(2022, month, day);
+    }
+
+    public static int _daysTogether(
+        LocalDate from, LocalDate to, LocalDate _to) {
+        if (to.compareTo(_to) > 0) {
+            to = _to;
+        }
+
+        long days = ChronoUnit.DAYS.between(from, to);
+        return (int)days + 1;
+    }
+}