-
Notifications
You must be signed in to change notification settings - Fork 0
/
NumberOfMondaysInMonth.java
214 lines (195 loc) · 5.28 KB
/
NumberOfMondaysInMonth.java
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
package com.javamultiplex.datetime;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Calendar;
import java.util.Date;
import java.util.List;
import java.util.Scanner;
//How to find number of mondays in given month?
public class NumberOfMondaysInMonth {
/*
* d -> day of month
* M -> month of year
* y -> year
*/
private static final String pattern="dd/MM/yyyy";
public static void main(String[] args) {
Scanner input = null;
try {
input = new Scanner(System.in);
System.out.println("Enter month name : ");
String monthName = input.next();
String year = null;
Date date=null;
String myDate=null;
List<String> dates=new ArrayList<>();
DateFormat format=new SimpleDateFormat(pattern);
int dayAndMonthNumber[] = new int[2];
int days = 0,monthNumber=0,mondays=0;
// Converting String to uppercase
monthName = monthName.toUpperCase();
System.out.println("Enter Year (yyyy) : ");
year = input.next();
if (isValidMonth(monthName) && isValidYear(year)) {
dayAndMonthNumber = getNumberofDaysAndMonthNumberByMonthName(
monthName, year);
days = dayAndMonthNumber[0];
monthNumber = dayAndMonthNumber[1];
// Converting String to int.
int myYear = Integer.parseInt(year);
// Creating Calendar class instance.
Calendar cal = Calendar.getInstance();
// Adding given month and year in Calendar.
cal.set(Calendar.MONTH, monthNumber);
cal.set(Calendar.YEAR, myYear);
/*
*
* Adding all the dates related to given month and year to Calendar.
* and checking day for each date.
* If it is Monday then increase the counter and print date.
*
*/
for (int i = 1; i <= days; i++) {
// Adding day of month in Calendar.
cal.set(Calendar.DAY_OF_MONTH, i);
/*
* cal.get(Calendar.DAY_OF_WEEK) = 1 (Sunday)
* cal.get(Calendar.DAY_OF_WEEK) = 2 (Monday)
* cal.get(Calendar.DAY_OF_WEEK) = 3 (Tuesday)
* cal.get(Calendar.DAY_OF_WEEK) = 4 (Wednesday)
* cal.get(Calendar.DAY_OF_WEEK) = 5 (Thursday)
* cal.get(Calendar.DAY_OF_WEEK) = 6 (Friday)
* cal.get(Calendar.DAY_OF_WEEK) = 7 (Saturday)
*/
if (cal.get(Calendar.DAY_OF_WEEK) == 2)
{
date=cal.getTime();
myDate=format.format(date);
dates.add(myDate);
mondays++;
}
}
System.out.println("Number of Mondays : "+mondays);
System.out.println("Dates are as follows :");
for(int i=0;i<mondays;i++)
{
System.out.println(dates.get(i));
}
} else {
System.out
.println("Month name should be valid and Year should be 4 digit long.");
}
} finally {
if (input != null) {
input.close();
}
}
}
private static int[] getNumberofDaysAndMonthNumberByMonthName(
String monthName, String year) {
int dayAndMonthNumber[] = new int[2];
int days = 0;
int monthNumber = 0;
switch (monthName) {
case "JANUARY":
case "JAN":
days = 31;
monthNumber = 0;
break;
case "FEBRUARY":
case "FEB":
if (isLeapYear(year)) {
days = 29;
} else {
days = 28;
}
monthNumber = 1;
break;
case "MARCH":
case "MAR":
days = 31;
monthNumber = 2;
break;
case "APRIL":
case "APR":
days = 30;
monthNumber = 3;
break;
case "MAY":
days = 31;
monthNumber = 4;
break;
case "JUNE":
days = 30;
monthNumber = 5;
break;
case "JULY":
days = 31;
monthNumber = 6;
break;
case "AUGUST":
case "AUG":
days = 31;
monthNumber = 7;
break;
case "SEPTEMBER":
case "SEP":
days = 30;
monthNumber = 8;
break;
case "OCTOBER":
case "OCT":
days = 31;
monthNumber = 9;
break;
case "NOVEMBER":
case "NOV":
days = 30;
monthNumber = 10;
break;
case "DECEMBER":
case "DEC":
days = 31;
monthNumber = 11;
break;
}
dayAndMonthNumber[0] = days;
dayAndMonthNumber[1] = monthNumber;
return dayAndMonthNumber;
}
private static boolean isLeapYear(String year) {
boolean result = false;
// Converting String to int.
int myYear = Integer.parseInt(year);
if ((myYear % 4 == 0 && myYear % 100 != 0) || myYear % 400 == 0) {
result = true;
}
return result;
}
private static boolean isValidMonth(String monthName) {
boolean result = false;
String[] fullMonthNames = { "JANUARY", "FEBRUARY", "MARCH", "APRIL",
"MAY", "JUNE", "JULY", "AUGUST", "SEPTEMBER", "OCTOBER",
"NOVEMBER", "DECEMBER" };
String[] halfMonthNames = { "JAN", "FEB", "MAR", "APR", "AUG", "SEP",
"OCT", "NOV", "DEC" };
// Converting Array to List
List<String> fullMonths = new ArrayList<>(Arrays.asList(fullMonthNames));
List<String> halfMonths = new ArrayList<>(Arrays.asList(halfMonthNames));
if (fullMonths.contains(monthName) || halfMonths.contains(monthName)) {
result = true;
}
return result;
}
private static boolean isValidYear(String year) {
boolean result = false;
// Regular expression that matches a String contains 4 digits.
String pattern = "[0-9]{4}";
if (year.matches(pattern)) {
result = true;
}
return result;
}
}