{"id":2096,"date":"2020-06-29T11:57:36","date_gmt":"2020-06-29T02:57:36","guid":{"rendered":"https:\/\/loglog.xyz\/?p=2096"},"modified":"2020-06-29T11:57:36","modified_gmt":"2020-06-29T02:57:36","slug":"usage_treeset","status":"publish","type":"post","link":"https:\/\/loglog.xyz\/programming\/usage_treeset","title":{"rendered":"\u3010Java\u3011TreeSet\u306e\u4f7f\u3044\u65b9\uff08\u9806\u5e8f\u4ed8\u3051Set\uff09"},"content":{"rendered":"<h2>TreeSet\u306e\u4f7f\u3044\u65b9<\/h2>\n<p>\u57fa\u672c\u7684\u306a\u4f7f\u3044\u65b9\u306fHashSet\u3068\u540c\u3058\u306a\u306e\u3067\u3001\u4ee5\u4e0b\u3092\u53c2\u7167\u4e0b\u3055\u3044\u3002<br \/>\n<a href=\"https:\/\/loglog.xyz\/programming\/usage_hashset\" title=\"\u3010Java\u3011HashSet\u306e\u4f7f\u3044\u65b9\u3044\u308d\u3044\u308d\" rel=\"noopener noreferrer\" target=\"_blank\">\u3010Java\u3011HashSet\u306e\u4f7f\u3044\u65b9\u3044\u308d\u3044\u308d<\/a><\/p>\n<p>TreeSet\u306f\u4f55\u3082\u6307\u5b9a\u305b\u305a\u306b\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u751f\u6210\u3059\u308b\u3068\u3001Collections.sort\u306b\u3088\u308b\u9806\u5e8f\u4ed8\u3051\u304c\u306a\u3055\u308c\u308bSet\u3067\u3059\u3002<br \/>\n\u3053\u3053\u3067\u306f\u3001\u4ed6\u306eSet\u3068\u306e\u9055\u3044\u3068\u9806\u5e8f\u4ed8\u3051\u3092\u3069\u306e\u3088\u3046\u306b\u5b9a\u7fa9\u3059\u308b\u304b\u306b\u3064\u3044\u3066\u8aac\u660e\u3057\u307e\u3059\u3002<\/p>\n<h2>HashSet\u3001LinkedHashSet\u3068\u306e\u9055\u3044<\/h2>\n<p>Set\uff08\u5171\u901a\u4ed5\u69d8\uff09\uff1a\u91cd\u8907\u3092\u3082\u305f\u306a\u3044\u5024\u306e\u96c6\u5408<br \/>\nHashSet\u3000\u3000\u3000 \uff1a\u9806\u5e8f\u3092\u3082\u305f\u306a\u3044Set<br \/>\nLinkedHashSet \uff1a\u633f\u5165\u9806\u3092\u4fdd\u6301\u3059\u308bSet<br \/>\n<span class=\"rmarker\">TreeSet\u3000\u3000\u3000\u3000\uff1a\u81ea\u7136\u9806\u5e8f\u4ed8\u3051\u3092\u3082\u3064Set\u3002\u307e\u305f\u72ec\u81ea\u306e\u9806\u5e8f\u4ed8\u3051\u3092\u5b9a\u7fa9\u53ef\u80fd\u3002<\/span><\/p>\n<h2>TreeSet\u306e\u81ea\u7136\u9806\u5e8f\u4ed8\u3051<\/h2>\n<p>\u81ea\u7136\u9806\u5e8f\u306fCamparable\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u306b\u3088\u3063\u3066\u5f37\u5236\u3055\u308c\u3001Collections.sort\u306b\u3088\u308b\u9806\u5e8f\u4ed8\u3051\u304c\u306a\u3055\u308c\u307e\u3059\u3002<br \/>\n\u4f8b\u3048\u3070\u3001\u30a2\u30eb\u30d5\u30a1\u30d9\u30c3\u30c8\u3092\u9806\u4e0d\u540c\u3067\u633f\u5165\u3057\u3066\u3082\u3001\u53d6\u308a\u51fa\u3059\u3068\u304d\u306f\u300cA\u300d\u304b\u3089\u4e26\u3093\u3067\u3044\u307e\u3059\u3002<br \/>\n\u6570\u5024\u3067\u3042\u308c\u3070\u3001\u5c0f\u3055\u3044\u5024\uff08\u6607\u9806\uff09\u306b\u306a\u3063\u3066\u3044\u307e\u3059\u3002<\/p>\n<p>\u3053\u308c\u306f\u964d\u9806\u306b\u3059\u308b\u3053\u3068\u3082\u53ef\u80fd\u3067\u3059\u3002<br \/>\n\u307e\u305f\u3001Comparator\u3092\u6307\u5b9a\u3059\u308b\u3053\u3068\u3067\u9806\u5e8f\u4ed8\u3051\u3092\u72ec\u81ea\u306b\u5b9a\u7fa9\u53ef\u80fd\u3067\u3059\u3002<\/p>\n<p>\u5b9f\u969b\u306b\u30b3\u30fc\u30c9\u3067\u78ba\u8a8d\u3057\u307e\u3059\u3002<\/p>\n<h2>\u30b3\u30fc\u30c9\u3067\u78ba\u8a8d<\/h2>\n<h3>\u81ea\u7136\u9806\u5e8f\u4ed8\u3051<\/h3>\n<pre class=\"lang:java decode:true \" >PrintStream out = System.out;\r\n\r\n\/\/ \u30a2\u30eb\u30d5\u30a1\u30d9\u30c3\u30c8\r\nSet&lt;String&gt; alphaTree = new TreeSet&lt;&gt;();\r\nalphaTree.add(\"B\");\r\nalphaTree.add(\"C\");\r\nalphaTree.add(\"A\");\r\nout.println(\"alphaTree : \" + alphaTree);\r\n\r\n\/\/ \u6570\u5024\r\nSet&lt;Integer&gt; numTree = new TreeSet&lt;&gt;();\r\nnumTree.add(new Integer(2));\r\nnumTree.add(new Integer(1));\r\nnumTree.add(new Integer(3));\r\nout.println(\"numTree : \" + numTree);\r\n\r\n\/\/ \u5b9f\u884c\u7d50\u679c\r\nalphaTree : [A, B, C]\r\nnumTree : [1, 2, 3]<\/pre>\n<p>\u30a2\u30eb\u30d5\u30a1\u30d9\u30c3\u30c8\u3092\u300cB\u2192C\u2192A\u300d\u3068\u633f\u5165\u3057\u3066\u3082\u3001\u53d6\u308a\u51fa\u3059\u969b\u306b\u306f\u300cA\u2192B\u2192C\u300d\u3068\u306a\u3063\u3066\u3044\u307e\u3059\u3002<br \/>\n\u307e\u305f\u3001\u6570\u5024\u3082\u540c\u69d8\u306b\u300c2\u21921\u21923\u300d\u3068\u633f\u5165\u3057\u3066\u3082\u3001\u300c1\u21922\u21923\u300d\u3068\u306a\u3063\u3066\u3044\u307e\u3059\u3002<\/p>\n<h3>\u964d\u9806<\/h3>\n<p>\u6b21\u306f\u964d\u9806\u306b\u3059\u308b\u65b9\u6cd5\u3067\u3059\u3002<\/p>\n<pre class=\"lang:java decode:true \" >PrintStream out = System.out;\r\n\r\n\/\/ \u964d\u9806\r\nout.println(\"reverse alphaTree : \" + alphaTree.stream()\r\n        .sorted(Comparator.reverseOrder())\r\n        .collect(Collectors.toList()));\r\nout.println(\"reverse numTree : \" + numTree.stream()\r\n        .sorted(Comparator.reverseOrder())\r\n        .collect(Collectors.toList()));\r\n\r\n\/\/ \u5b9f\u884c\u7d50\u679c\r\nreverse alphaTree : [C, B, A]\r\nreverse numTree : [3, 2, 1]<\/pre>\n<p>stream\u306f\u3001Java SE 8\u304b\u3089\u8ffd\u52a0\u3055\u308c\u305f\u30a4\u30c6\u30ec\u30fc\u30b7\u30e7\u30f3\u306e\u62e1\u5f35API\u3067\u3059\u3002<br \/>\nstream()\u3067\u8fd4\u3055\u308c\u305f\u30b3\u30ec\u30af\u30b7\u30e7\u30f3\u306b\u5bfe\u3057\u3001sorted(Comparator.reverseOrder())\u3067\u964d\u9806\u3092\u6307\u5b9a\u3057\u307e\u3059\u3002<br \/>\n\u66f4\u306b\u3001collect(Collectors.toList())\u3067\u30bd\u30fc\u30c8\u3057\u305f\u9806\u306eList\u306b\u3057\u3066\u8fd4\u3057\u307e\u3059\u3002<\/p>\n<h3>Comparator\u3092\u6307\u5b9a<\/h3>\n<pre class=\"lang:java decode:true \" >PrintStream out = System.out;\r\n\r\n\/\/ Comparator\u3092\u6307\u5b9a\uff08length\u306e\u307f\uff09\r\nComparator&lt;String&gt; lenComparator = Comparator.comparing(String::length);\r\nSet&lt;String&gt; lenTree = new TreeSet&lt;&gt;(lenComparator);\r\nlenTree.add(\"11\");\r\nlenTree.add(\"22\");\r\nlenTree.add(\"AAA\");\r\nlenTree.add(\"aaa\");\r\nlenTree.add(\"BBBB\");\r\nlenTree.add(\"bbbb\");\r\nout.println(\"lenTree : \" + lenTree);\r\n\r\n\/\/ Comparator\u3092\u6307\u5b9a\uff08length\u3068hashcode\uff09\r\nComparator&lt;String&gt; comparator = Comparator.comparing(String::length)\r\n        .thenComparing(String::hashCode);\r\nSet&lt;String&gt; lenHashTree = new TreeSet&lt;&gt;(comparator);\r\nlenHashTree.add(\"11\");\r\nlenHashTree.add(\"22\");\r\nlenHashTree.add(\"AAA\");\r\nlenHashTree.add(\"aaa\");\r\nlenHashTree.add(\"BBBB\");\r\nlenHashTree.add(\"bbbb\");\r\nout.println(\"lenHashTree : \" + lenHashTree);\r\n\r\n\/\/ \u4e8b\u9805\u7d50\u679c\r\nlenTree : [11, AAA, BBBB]\r\nlenHashTree : [11, 22, AAA, aaa, BBBB, bbbb]\r\n<\/pre>\n<p><strong>Comparator\u3092\u6307\u5b9a\uff08length\u306e\u307f\uff09<\/strong>\u3067\u5b9a\u7fa9\u3057\u305f\u7d50\u679c\u3001\u300c22\u300d\u300caaa\u300d\u300cbbbb\u300d\u306f\u7121\u304f\u306a\u3063\u3066\u3044\u307e\u3059\u3002<br \/>\n\u3053\u308c\u306f\u683c\u7d0d\u3055\u308c\u308b\u5024\u304cComparator\u306b\u3088\u3063\u3066\u3001length()\u3060\u3051\u3067\u7b49\u4fa1\u3067\u3042\u308b\u304b\u3092\u5224\u65ad\u3057\u3066\u3044\u308b\u305f\u3081\u3067\u3059\u3002<br \/>\n\u6587\u5b57\u5217\u9577\u306e\u307f\u3092\u5224\u5b9a\u57fa\u6e96\u306b\u3059\u308b\u305f\u3081\u3001\u300c22\u300d\u300caaa\u300d\u300cbbbb\u300d\u306f\u3001<br \/>\n\u3059\u3067\u306b\u683c\u7d0d\u6e08\u307f\u306e\u300c11\u300d\u300cAAA\u300d\u300cBBBB\u300d\u3068\u7b49\u4fa1\u3068\u5224\u65ad\u3055\u308c\u305f\u3053\u3068\u3067\u8ffd\u52a0\u3055\u308c\u307e\u305b\u3093\u3067\u3057\u305f\u3002<\/p>\n<div class=\"inyoumodoki\">\uff1cJava Doc\u304b\u3089\u306e\u5f15\u7528\uff1e<br \/>\nTreeSet\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u306f\u305d\u306ecompareTo\u30e1\u30bd\u30c3\u30c9\u307e\u305f\u306fcompare\u30e1\u30bd\u30c3\u30c9\u3092\u4f7f\u7528\u3057\u3066\u3059\u3079\u3066\u306e\u8981\u7d20\u6bd4\u8f03\u3092\u5b9f\u884c\u3059\u308b\u306e\u3067\u3001\u3053\u306e\u30e1\u30bd\u30c3\u30c9\u306b\u3088\u3063\u3066\u7b49\u4fa1\u3068\u898b\u306a\u3055\u308c\u308b2\u3064\u306e\u8981\u7d20\u306f\u3001\u30bb\u30c3\u30c8\u306e\u898b\u5730\u304b\u3089\u3059\u308c\u3070\u540c\u3058\u3082\u306e\u3067\u3059\u3002<br \/>\n<a href=\"https:\/\/docs.oracle.com\/javase\/jp\/8\/docs\/api\/java\/util\/TreeSet.html\" title=\"\u30af\u30e9\u30b9TreeSet&lt;E&gt;\" rel=\"noopener noreferrer\" target=\"_blank\">\u30af\u30e9\u30b9TreeSet<E><\/a><\/div>\n<p><strong>Comparator\u3092\u6307\u5b9a\uff08length\u3068hashcode\uff09<\/strong>\u306e\u3088\u3046\u306b\u3001<br \/>\nhashcode()\u3067\u6587\u5b57\u5217\u306e\u30cf\u30c3\u30b7\u30e5\u30fb\u30b3\u30fc\u30c9\u5024\u3092\u7b97\u51fa\u3059\u308b\u6761\u4ef6\u3092\u8ffd\u52a0\u3059\u308c\u3070\u56de\u907f\u3067\u304d\u307e\u3059\u3002<br \/>\n\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u3001\u30cf\u30c3\u30b7\u30e5\u30fb\u30b3\u30fc\u30c9\u5024\u306f\u6587\u5b57\u6bce\u306b\u7570\u306a\u308b\u5024\u3092\u7b97\u51fa\u3059\u308b\u304b\u3089\u3067\u3059\u3002<\/p>\n<pre class=\"lang:java decode:true \" >PrintStream out = System.out;\r\n\r\nout.println(\"AAA : \" + \"AAA\".hashCode());\r\nout.println(\"aaa : \" + \"aaa\".hashCode());\r\n\r\n\/\/ \u30cf\u30c3\u30b7\u30e5\u30b3\u30fc\u30c9\u5024\r\nAAA : 64545\r\naaa : 96321<\/pre>\n<h2>TreeSet\u306e\u4f7f\u3044\u3069\u3053\u308d<\/h2>\n<p>\u9806\u5e8f\u4ed8\u3051\u3092\u5fc5\u8981\u3068\u3059\u308bSet\uff08\u91cd\u8907\u306e\u306a\u3044\u96c6\u5408\uff09\u3092\u6271\u3044\u305f\u3044\u5834\u5408\u306b\u6709\u52b9\u3068\u8003\u3048\u307e\u3059\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>TreeSet\u306e\u4f7f\u3044\u65b9 \u57fa\u672c\u7684\u306a\u4f7f\u3044\u65b9\u306fHashSet\u3068\u540c\u3058\u306a\u306e\u3067\u3001\u4ee5\u4e0b\u3092\u53c2\u7167\u4e0b\u3055\u3044\u3002 \u3010Java\u3011HashSet\u306e\u4f7f\u3044\u65b9\u3044\u308d\u3044\u308d TreeSet\u306f\u4f55\u3082\u6307\u5b9a\u305b\u305a\u306b\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u751f\u6210\u3059\u308b\u3068\u3001Collections.sort [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":2082,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"swell_btn_cv_data":"{\"3a0ddb8a\":{\"pv\":1173,\"imp\":628}}","footnotes":""},"categories":[2,65],"tags":[54,125,126],"class_list":["post-2096","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-programming","category-java","tag-java","tag-treeset","tag-collection"],"_links":{"self":[{"href":"https:\/\/loglog.xyz\/wp-json\/wp\/v2\/posts\/2096","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/loglog.xyz\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/loglog.xyz\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/loglog.xyz\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/loglog.xyz\/wp-json\/wp\/v2\/comments?post=2096"}],"version-history":[{"count":7,"href":"https:\/\/loglog.xyz\/wp-json\/wp\/v2\/posts\/2096\/revisions"}],"predecessor-version":[{"id":2103,"href":"https:\/\/loglog.xyz\/wp-json\/wp\/v2\/posts\/2096\/revisions\/2103"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/loglog.xyz\/wp-json\/wp\/v2\/media\/2082"}],"wp:attachment":[{"href":"https:\/\/loglog.xyz\/wp-json\/wp\/v2\/media?parent=2096"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/loglog.xyz\/wp-json\/wp\/v2\/categories?post=2096"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/loglog.xyz\/wp-json\/wp\/v2\/tags?post=2096"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}