344 lines
10 KiB
Java
344 lines
10 KiB
Java
// onjava/Countries.java
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// (c)2021 MindView LLC: see Copyright.txt
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// We make no guarantees that this code is fit for any purpose.
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// Visit http://OnJava8.com for more book information.
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// "Flyweight" Maps and Lists of sample data
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// {java onjava.Countries}
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package onjava;
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import java.util.*;
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public class Countries {
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public static final String[][] DATA = {
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// Africa
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{"ALGERIA","Algiers"},
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{"ANGOLA","Luanda"},
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{"BENIN","Porto-Novo"},
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{"BOTSWANA","Gaberone"},
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{"BURKINA FASO","Ouagadougou"},
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{"BURUNDI","Bujumbura"},
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{"CAMEROON","Yaounde"},
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{"CAPE VERDE","Praia"},
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{"CENTRAL AFRICAN REPUBLIC","Bangui"},
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{"CHAD","N'djamena"},
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{"COMOROS","Moroni"},
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{"CONGO","Brazzaville"},
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{"DJIBOUTI","Dijibouti"},
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{"EGYPT","Cairo"},
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{"EQUATORIAL GUINEA","Malabo"},
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{"ERITREA","Asmara"},
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{"ETHIOPIA","Addis Ababa"},
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{"GABON","Libreville"},
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{"THE GAMBIA","Banjul"},
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{"GHANA","Accra"},
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{"GUINEA","Conakry"},
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{"BISSAU","Bissau"},
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{"COTE D'IVOIR (IVORY COAST)","Yamoussoukro"},
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{"KENYA","Nairobi"},
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{"LESOTHO","Maseru"},
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{"LIBERIA","Monrovia"},
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{"LIBYA","Tripoli"},
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{"MADAGASCAR","Antananarivo"},
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{"MALAWI","Lilongwe"},
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{"MALI","Bamako"},
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{"MAURITANIA","Nouakchott"},
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{"MAURITIUS","Port Louis"},
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{"MOROCCO","Rabat"},
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{"MOZAMBIQUE","Maputo"},
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{"NAMIBIA","Windhoek"},
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{"NIGER","Niamey"},
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{"NIGERIA","Abuja"},
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{"RWANDA","Kigali"},
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{"SAO TOME E PRINCIPE","Sao Tome"},
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{"SENEGAL","Dakar"},
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{"SEYCHELLES","Victoria"},
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{"SIERRA LEONE","Freetown"},
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{"SOMALIA","Mogadishu"},
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{"SOUTH AFRICA","Pretoria/Cape Town"},
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{"SUDAN","Khartoum"},
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{"SWAZILAND","Mbabane"},
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{"TANZANIA","Dodoma"},
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{"TOGO","Lome"},
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{"TUNISIA","Tunis"},
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{"UGANDA","Kampala"},
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{"DEMOCRATIC REPUBLIC OF THE CONGO (ZAIRE)",
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"Kinshasa"},
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{"ZAMBIA","Lusaka"},
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{"ZIMBABWE","Harare"},
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// Asia
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{"AFGHANISTAN","Kabul"},
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{"BAHRAIN","Manama"},
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{"BANGLADESH","Dhaka"},
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{"BHUTAN","Thimphu"},
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{"BRUNEI","Bandar Seri Begawan"},
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{"CAMBODIA","Phnom Penh"},
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{"CHINA","Beijing"},
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{"CYPRUS","Nicosia"},
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{"INDIA","New Delhi"},
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{"INDONESIA","Jakarta"},
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{"IRAN","Tehran"},
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{"IRAQ","Baghdad"},
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{"ISRAEL","Jerusalem"},
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{"JAPAN","Tokyo"},
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{"JORDAN","Amman"},
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{"KUWAIT","Kuwait City"},
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{"LAOS","Vientiane"},
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{"LEBANON","Beirut"},
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{"MALAYSIA","Kuala Lumpur"},
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{"THE MALDIVES","Male"},
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{"MONGOLIA","Ulan Bator"},
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{"MYANMAR (BURMA)","Rangoon"},
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{"NEPAL","Katmandu"},
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{"NORTH KOREA","P'yongyang"},
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{"OMAN","Muscat"},
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{"PAKISTAN","Islamabad"},
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{"PHILIPPINES","Manila"},
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{"QATAR","Doha"},
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{"SAUDI ARABIA","Riyadh"},
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{"SINGAPORE","Singapore"},
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{"SOUTH KOREA","Seoul"},
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{"SRI LANKA","Colombo"},
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{"SYRIA","Damascus"},
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{"TAIWAN (REPUBLIC OF CHINA)","Taipei"},
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{"THAILAND","Bangkok"},
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{"TURKEY","Ankara"},
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{"UNITED ARAB EMIRATES","Abu Dhabi"},
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{"VIETNAM","Hanoi"},
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{"YEMEN","Sana'a"},
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// Australia and Oceania
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{"AUSTRALIA","Canberra"},
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{"FIJI","Suva"},
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{"KIRIBATI","Bairiki"},
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{"MARSHALL ISLANDS","Dalap-Uliga-Darrit"},
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{"MICRONESIA","Palikir"},
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{"NAURU","Yaren"},
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{"NEW ZEALAND","Wellington"},
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{"PALAU","Koror"},
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{"PAPUA NEW GUINEA","Port Moresby"},
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{"SOLOMON ISLANDS","Honaira"},
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{"TONGA","Nuku'alofa"},
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{"TUVALU","Fongafale"},
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{"VANUATU","Port Vila"},
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{"WESTERN SAMOA","Apia"},
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// Eastern Europe and former USSR
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{"ARMENIA","Yerevan"},
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{"AZERBAIJAN","Baku"},
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{"BELARUS (BYELORUSSIA)","Minsk"},
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{"BULGARIA","Sofia"},
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{"GEORGIA","Tbilisi"},
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{"KAZAKSTAN","Almaty"},
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{"KYRGYZSTAN","Alma-Ata"},
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{"MOLDOVA","Chisinau"},
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{"RUSSIA","Moscow"},
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{"TAJIKISTAN","Dushanbe"},
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{"TURKMENISTAN","Ashkabad"},
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{"UKRAINE","Kyiv"},
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{"UZBEKISTAN","Tashkent"},
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// Europe
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{"ALBANIA","Tirana"},
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{"ANDORRA","Andorra la Vella"},
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{"AUSTRIA","Vienna"},
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{"BELGIUM","Brussels"},
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{"BOSNIA-HERZEGOVINA","Sarajevo"},
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{"CROATIA","Zagreb"},
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{"CZECH REPUBLIC","Prague"},
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{"DENMARK","Copenhagen"},
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{"ESTONIA","Tallinn"},
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{"FINLAND","Helsinki"},
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{"FRANCE","Paris"},
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{"GERMANY","Berlin"},
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{"GREECE","Athens"},
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{"HUNGARY","Budapest"},
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{"ICELAND","Reykjavik"},
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{"IRELAND","Dublin"},
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{"ITALY","Rome"},
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{"LATVIA","Riga"},
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{"LIECHTENSTEIN","Vaduz"},
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{"LITHUANIA","Vilnius"},
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{"LUXEMBOURG","Luxembourg"},
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{"MACEDONIA","Skopje"},
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{"MALTA","Valletta"},
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{"MONACO","Monaco"},
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{"MONTENEGRO","Podgorica"},
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{"THE NETHERLANDS","Amsterdam"},
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{"NORWAY","Oslo"},
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{"POLAND","Warsaw"},
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{"PORTUGAL","Lisbon"},
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{"ROMANIA","Bucharest"},
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{"SAN MARINO","San Marino"},
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{"SERBIA","Belgrade"},
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{"SLOVAKIA","Bratislava"},
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{"SLOVENIA","Ljuijana"},
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{"SPAIN","Madrid"},
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{"SWEDEN","Stockholm"},
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{"SWITZERLAND","Berne"},
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{"UNITED KINGDOM","London"},
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{"VATICAN CITY","Vatican City"},
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// North and Central America
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{"ANTIGUA AND BARBUDA","Saint John's"},
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{"BAHAMAS","Nassau"},
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{"BARBADOS","Bridgetown"},
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{"BELIZE","Belmopan"},
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{"CANADA","Ottawa"},
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{"COSTA RICA","San Jose"},
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{"CUBA","Havana"},
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{"DOMINICA","Roseau"},
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{"DOMINICAN REPUBLIC","Santo Domingo"},
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{"EL SALVADOR","San Salvador"},
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{"GRENADA","Saint George's"},
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{"GUATEMALA","Guatemala City"},
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{"HAITI","Port-au-Prince"},
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{"HONDURAS","Tegucigalpa"},
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{"JAMAICA","Kingston"},
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{"MEXICO","Mexico City"},
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{"NICARAGUA","Managua"},
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{"PANAMA","Panama City"},
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{"ST. KITTS AND NEVIS","Basseterre"},
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{"ST. LUCIA","Castries"},
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{"ST. VINCENT AND THE GRENADINES","Kingstown"},
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{"UNITED STATES OF AMERICA","Washington, D.C."},
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// South America
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{"ARGENTINA","Buenos Aires"},
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{"BOLIVIA","Sucre (legal)/La Paz(administrative)"},
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{"BRAZIL","Brasilia"},
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{"CHILE","Santiago"},
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{"COLOMBIA","Bogota"},
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{"ECUADOR","Quito"},
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{"GUYANA","Georgetown"},
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{"PARAGUAY","Asuncion"},
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{"PERU","Lima"},
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{"SURINAME","Paramaribo"},
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{"TRINIDAD AND TOBAGO","Port of Spain"},
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{"URUGUAY","Montevideo"},
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{"VENEZUELA","Caracas"},
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};
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// Use AbstractMap by implementing entrySet()
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private static class FlyweightMap
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extends AbstractMap<String,String> {
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private static class Entry
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implements Map.Entry<String,String> {
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int index;
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Entry(int index) { this.index = index; }
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@Override public boolean equals(Object o) {
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return o instanceof FlyweightMap &&
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Objects.equals(DATA[index][0], o);
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}
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@Override public int hashCode() {
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return Objects.hashCode(DATA[index][0]);
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}
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@Override
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public String getKey() { return DATA[index][0]; }
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@Override public String getValue() {
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return DATA[index][1];
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}
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@Override public String setValue(String value) {
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throw new UnsupportedOperationException();
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}
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}
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// Implement size() & iterator() for AbstractSet:
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static class EntrySet
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extends AbstractSet<Map.Entry<String,String>> {
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private int size;
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EntrySet(int size) {
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if(size < 0)
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this.size = 0;
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// Can't be any bigger than the array:
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else if(size > DATA.length)
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this.size = DATA.length;
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else
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this.size = size;
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}
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@Override public int size() { return size; }
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private class Iter
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implements Iterator<Map.Entry<String,String>> {
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// Only one Entry object per Iterator:
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private Entry entry = new Entry(-1);
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@Override public boolean hasNext() {
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return entry.index < size - 1;
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}
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@Override
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public Map.Entry<String,String> next() {
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entry.index++;
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return entry;
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}
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@Override public void remove() {
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throw new UnsupportedOperationException();
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}
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}
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@Override public
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Iterator<Map.Entry<String,String>> iterator() {
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return new Iter();
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}
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}
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private static
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Set<Map.Entry<String,String>> entries =
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new EntrySet(DATA.length);
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@Override
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public Set<Map.Entry<String,String>> entrySet() {
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return entries;
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}
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}
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// Create a partial map of 'size' countries:
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static Map<String,String> select(final int size) {
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return new FlyweightMap() {
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@Override
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public Set<Map.Entry<String,String>> entrySet() {
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return new EntrySet(size);
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}
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};
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}
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static Map<String,String> map = new FlyweightMap();
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public static Map<String,String> capitals() {
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return map; // The entire map
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}
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public static Map<String,String> capitals(int size) {
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return select(size); // A partial map
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}
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static List<String> names =
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new ArrayList<>(map.keySet());
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// All the names:
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public static List<String> names() { return names; }
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// A partial list:
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public static List<String> names(int size) {
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return new ArrayList<>(select(size).keySet());
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}
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public static void main(String[] args) {
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System.out.println(capitals(10));
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System.out.println(names(10));
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System.out.println(new HashMap<>(capitals(3)));
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System.out.println(
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new LinkedHashMap<>(capitals(3)));
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System.out.println(new TreeMap<>(capitals(3)));
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System.out.println(new Hashtable<>(capitals(3)));
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System.out.println(new HashSet<>(names(6)));
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System.out.println(new LinkedHashSet<>(names(6)));
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System.out.println(new TreeSet<>(names(6)));
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System.out.println(new ArrayList<>(names(6)));
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System.out.println(new LinkedList<>(names(6)));
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System.out.println(capitals().get("BRAZIL"));
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}
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}
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/* Output:
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{ALGERIA=Algiers, ANGOLA=Luanda, BENIN=Porto-Novo,
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BOTSWANA=Gaberone, BURKINA FASO=Ouagadougou,
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BURUNDI=Bujumbura, CAMEROON=Yaounde, CAPE VERDE=Praia,
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CENTRAL AFRICAN REPUBLIC=Bangui, CHAD=N'djamena}
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[ALGERIA, ANGOLA, BENIN, BOTSWANA, BURKINA FASO,
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BURUNDI, CAMEROON, CAPE VERDE, CENTRAL AFRICAN
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REPUBLIC, CHAD]
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{BENIN=Porto-Novo, ANGOLA=Luanda, ALGERIA=Algiers}
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{ALGERIA=Algiers, ANGOLA=Luanda, BENIN=Porto-Novo}
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{ALGERIA=Algiers, ANGOLA=Luanda, BENIN=Porto-Novo}
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{ALGERIA=Algiers, ANGOLA=Luanda, BENIN=Porto-Novo}
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[BENIN, BOTSWANA, ANGOLA, BURKINA FASO, ALGERIA,
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BURUNDI]
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[ALGERIA, ANGOLA, BENIN, BOTSWANA, BURKINA FASO,
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BURUNDI]
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[ALGERIA, ANGOLA, BENIN, BOTSWANA, BURKINA FASO,
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BURUNDI]
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[ALGERIA, ANGOLA, BENIN, BOTSWANA, BURKINA FASO,
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BURUNDI]
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[ALGERIA, ANGOLA, BENIN, BOTSWANA, BURKINA FASO,
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BURUNDI]
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Brasilia
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*/
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