{"id":27444,"date":"2024-10-27T14:11:41","date_gmt":"2024-10-27T14:11:41","guid":{"rendered":"http:\/\/atmokpo.com\/w\/?p=27444"},"modified":"2024-11-26T07:18:17","modified_gmt":"2024-11-26T07:18:17","slug":"c-%ec%bd%94%eb%94%a9%ed%85%8c%ec%8a%a4%ed%8a%b8-%ea%b0%95%ec%a2%8c-%ec%b5%9c%ec%86%8c-%ea%b3%b5%ed%86%b5-%ec%a1%b0%ec%83%81","status":"publish","type":"post","link":"https:\/\/atmokpo.com\/w\/27444\/","title":{"rendered":"C# \ucf54\ub529\ud14c\uc2a4\ud2b8 \uac15\uc88c, \ucd5c\uc18c \uacf5\ud1b5 \uc870\uc0c1"},"content":{"rendered":"

<\/p>\n

\uc548\ub155\ud558\uc138\uc694, \ucf54\ub529\ud14c\uc2a4\ud2b8 \uc900\ube44\uc0dd \uc5ec\ub7ec\ubd84! \uc624\ub298\uc740 \ucd5c\uc18c \uacf5\ud1b5 \uc870\uc0c1(LCA, Lowest Common Ancestor) \ubb38\uc81c\uc5d0 \ub300\ud574 \uae4a\uc774 \uc788\uac8c \uc54c\uc544\ubcf4\uaca0\uc2b5\ub2c8\ub2e4. \uc774 \ubb38\uc81c\ub294 \ud2b8\ub9ac \uad6c\uc870\uc640 \uad00\ub828\uc774 \uc788\uc73c\uba70, \uc54c\uace0\ub9ac\uc998 \ubc0f \ub370\uc774\ud130 \uad6c\uc870\uc5d0 \ub300\ud55c \uae4a\uc740 \uc774\ud574\ub97c \uc694\uad6c\ud569\ub2c8\ub2e4. \uc6b0\ub9ac\ub294 \uc774 \ubb38\uc81c\ub97c \ub2e4\ub8e8\uba74\uc11c C#\uc73c\ub85c \ud574\uacb0\ud558\ub294 \ubc29\ubc95\ub3c4 \ud568\uaed8 \uc0b4\ud3b4\ubcf4\uaca0\uc2b5\ub2c8\ub2e4.<\/p>\n

\ubb38\uc81c \uc815\uc758<\/h2>\n

\uc8fc\uc5b4\uc9c4 \uc774\uc9c4 \ud2b8\ub9ac\uc5d0\uc11c \ub450 \ub178\ub4dc\uc758 \ucd5c\uc18c \uacf5\ud1b5 \uc870\uc0c1\uc744 \ucc3e\ub294 \ubb38\uc81c\uc785\ub2c8\ub2e4. \ub450 \ub178\ub4dc A\uc640 B\uac00 \uc8fc\uc5b4\uc84c\uc744 \ub54c, \uc774 \ub450 \ub178\ub4dc\uc758 \uc870\uc0c1\uc774 \ub418\ub294 \ub178\ub4dc \uc911 \uac00\uc7a5 \uae4a\uc774 \uc788\ub294 \ub178\ub4dc\ub97c \ucc3e\ub294 \uac83\uc774 \uc6b0\ub9ac\uc758 \ubaa9\ud45c\uc785\ub2c8\ub2e4.<\/p>\n

\uc608\uc81c<\/h2>\n
\n        \uc608\ub97c \ub4e4\uc5b4, \ub2e4\uc74c\uacfc \uac19\uc740 \uc774\uc9c4 \ud2b8\ub9ac\uac00 \uc874\uc7ac\ud55c\ub2e4\uace0 \uac00\uc815\ud574 \ubcf4\uaca0\uc2b5\ub2c8\ub2e4. \n\n              3\n             \/ \\\n            5   1\n           \/ \\ \/ \\\n          6  2 0  8\n            \/ \\\n           7   4\n\n        \ub178\ub4dc 5\uc640 \ub178\ub4dc 1\uc758 \ucd5c\uc18c \uacf5\ud1b5 \uc870\uc0c1\uc740 3\uc785\ub2c8\ub2e4.\n        \ub178\ub4dc 5\uc640 \ub178\ub4dc 2\uc758 \ucd5c\uc18c \uacf5\ud1b5 \uc870\uc0c1\uc740 5\uc785\ub2c8\ub2e4.\n        \ub178\ub4dc 6\uc640 \ub178\ub4dc 4\uc758 \ucd5c\uc18c \uacf5\ud1b5 \uc870\uc0c1\uc740 5\uc785\ub2c8\ub2e4.\n    <\/pre>\n
\ubb38\uc81c \uc811\uadfc \ubc29\ubc95<\/h2>\n
    \n
  1. \n
    \ud2b8\ub9ac \uad6c\uc870 \uc774\ud574<\/h3>\n
    \uc6b0\uc120, \uc774\uc9c4 \ud2b8\ub9ac\uc758 \uad6c\uc870\ub97c \uc774\ud574\ud574\uc57c \ud569\ub2c8\ub2e4. \uac01 \ub178\ub4dc\ub294 \ucd5c\ub300 \ub450 \uac1c\uc758 \uc790\uc2dd\uc744 \uac00\uc9c0\uba70, \uc67c\ucabd \uc11c\ube0c\ud2b8\ub9ac\uc640 \uc624\ub978\ucabd \uc11c\ube0c\ud2b8\ub9ac\ub85c \ub098\ub204\uc5b4\uc9c8 \uc218 \uc788\uc2b5\ub2c8\ub2e4. \ub178\ub4dc\ub97c \ucc3e\uae30 \uc704\ud574 \ud2b8\ub9ac\ub97c \ud0d0\uc0c9\ud558\ub294 \ubc29\ubc95\uc744 \uc54c\uace0 \uc788\uc5b4\uc57c \ud569\ub2c8\ub2e4.<\/p>\n<\/li>\n
  2. \n
    \uc7ac\uadc0\uc801 \uc811\uadfc<\/h3>\n
    \uc8fc\uc694 \uc811\uadfc \ubc29\uc2dd \uc911 \ud558\ub098\ub294 \uc7ac\uadc0\uc801\uc73c\ub85c \ud0d0\uc0c9\ud558\ub294 \uac83\uc785\ub2c8\ub2e4. \ub9cc\uc57d \ud604\uc7ac \ub178\ub4dc\uac00 A \ub610\ub294 B \uc911 \ud558\ub098\ub77c\uba74, \ud604\uc7ac \ub178\ub4dc\ub97c \ubc18\ud658\ud558\uace0, \uc67c\ucabd\uacfc \uc624\ub978\ucabd \uc11c\ube0c\ud2b8\ub9ac\ub97c \ud0d0\uc0c9\ud558\uc5ec \ub098\uba38\uc9c0 \ub178\ub4dc\ub97c \ucc3e\uc2b5\ub2c8\ub2e4. \ub458 \ub2e4 \ubc1c\uacac\ud558\uba74 \ud604\uc7ac \ub178\ub4dc\uac00 \ucd5c\uc18c \uacf5\ud1b5 \uc870\uc0c1\uc785\ub2c8\ub2e4.<\/p>\n<\/li>\n
  3. \n
    \ud2b8\ub9ac \ud0d0\uc0c9 \uc54c\uace0\ub9ac\uc998 \uc791\uc131<\/h3>\n
    \uc774\uc81c \uc54c\uace0\ub9ac\uc998\uc744 \uad6c\ud604\ud558\uae30 \uc704\ud574 C#\uc73c\ub85c \ucf54\ub4dc\ub97c \uc791\uc131\ud574\uc57c \ud569\ub2c8\ub2e4. \uc774 \uacfc\uc815\uc5d0\uc11c \uc7ac\uadc0\ub97c \uc0ac\uc6a9\ud558\uc5ec \ub178\ub4dc\ub97c \ud0d0\uc0c9\ud558\uace0 \ud655\uc778\ud558\ub294 \ubc29\ubc95\uc744 \ucf54\ub4dc\uc5d0 \ub179\uc544\ub0b4\ub9b4 \uac83\uc785\ub2c8\ub2e4.<\/p>\n<\/li>\n<\/ol>\n
    C# \ucf54\ub4dc \uad6c\ud604<\/h2>\n
    \n        \/\/ \uc774\uc9c4 \ud2b8\ub9ac \ub178\ub4dc \ud074\ub798\uc2a4 \uc815\uc758\n        public class TreeNode {\n            public int Value;\n            public TreeNode Left;\n            public TreeNode Right;\n\n            public TreeNode(int value) {\n                Value = value;\n                Left = null;\n                Right = null;\n            }\n        }\n\n        public class Solution {\n            public TreeNode LowestCommonAncestor(TreeNode root, TreeNode p, TreeNode q) {\n                \/\/ \uae30\uc800 \uc0ac\ub840: root\uac00 null\uc774\uac70\ub098 p \ub610\ub294 q\uc77c \uacbd\uc6b0, root\ub97c \ubc18\ud658\n                if (root == null || root == p || root == q) {\n                    return root;\n                }\n\n                \/\/ \uc67c\ucabd\uacfc \uc624\ub978\ucabd \uc11c\ube0c\ud2b8\ub9ac\uc5d0\uc11c \uac01 \ub178\ub4dc\ub97c \ud0d0\uc0c9\n                TreeNode left = LowestCommonAncestor(root.Left, p, q);\n                TreeNode right = LowestCommonAncestor(root.Right, p, q);\n\n                \/\/ p\uc640 q\uac00 \uac01\uac01 \ub2e4\ub978 \uc11c\ube0c\ud2b8\ub9ac\uc5d0 \uc788\uc744 \uacbd\uc6b0 \ud604\uc7ac \ub178\ub4dc\uac00 LCA\n                if (left != null && right != null) {\n                    return root;\n                }\n\n                \/\/ \ub458 \uc911 \ud558\ub098\ub9cc \ubc1c\uacac\ub41c \uacbd\uc6b0 \ud574\ub2f9 \ub178\ub4dc\ub97c \ubc18\ud658\n                return left ?? right;\n            }\n        }\n    <\/pre>\n
    \ucf54\ub4dc \uc124\uba85<\/h2>\n
    \uc774 \ucf54\ub4dc\ub294 \uc8fc\uc5b4\uc9c4 \uc774\uc9c4 \ud2b8\ub9ac\uc5d0\uc11c \ub450 \ub178\ub4dc\uc758 \ucd5c\uc18c \uacf5\ud1b5 \uc870\uc0c1\uc744 \ucc3e\uae30 \uc704\ud574 \uc791\uc131\ub418\uc5c8\uc2b5\ub2c8\ub2e4. \ub2e4\uc74c\uc740 \ucf54\ub4dc\uc758 \uc8fc\uc694 \ubd80\ubd84 \uc124\uba85\uc785\ub2c8\ub2e4:<\/p>\n
      \n
    1. \n
      TreeNode \ud074\ub798\uc2a4<\/h3>\n
      \uc774 \ud074\ub798\uc2a4\ub294 \ud2b8\ub9ac\uc758 \uac01 \ub178\ub4dc\ub97c \ub098\ud0c0\ub0c5\ub2c8\ub2e4. \uac01 \ub178\ub4dc\uc758 \uac12, \uc67c\ucabd \uc790\uc2dd \ub178\ub4dc, \uc624\ub978\ucabd \uc790\uc2dd \ub178\ub4dc\ub97c \uc800\uc7a5\ud569\ub2c8\ub2e4.<\/p>\n<\/li>\n
    2. \n
      LowestCommonAncestor \uba54\uc11c\ub4dc<\/h3>\n
      \uc774 \uba54\uc11c\ub4dc\ub294 \uc7ac\uadc0\uc801\uc73c\ub85c \ud638\ucd9c\ub418\uba70, \ud604\uc7ac \ub178\ub4dc\uac00 null\uc778 \uacbd\uc6b0\uc640 p \ub610\ub294 q\uc778 \uacbd\uc6b0\ub97c \ud655\uc778\ud569\ub2c8\ub2e4. \uc67c\ucabd\uacfc \uc624\ub978\ucabd \uc11c\ube0c\ud2b8\ub9ac\uc5d0\uc11c \uac01\uac01 p\uc640 q\ub97c \ucc3e\uace0, \ub450 \uc11c\ube0c\ud2b8\ub9ac\uc5d0\uc11c \ub458 \ub2e4 \ubc1c\uacac\ub418\uba74 \ud604\uc7ac \ub178\ub4dc\ub97c \ubc18\ud658\ud569\ub2c8\ub2e4.<\/p>\n<\/li>\n<\/ol>\n
      \ubcf5\uc7a1\ub3c4 \ubd84\uc11d<\/h2>\n
      \uc774 \uc54c\uace0\ub9ac\uc998\uc758 \uc2dc\uac04 \ubcf5\uc7a1\ub3c4\ub294 O(N)\uc785\ub2c8\ub2e4. N\uc740 \ud2b8\ub9ac\uc758 \ub178\ub4dc \uc218\uc774\uba70, \ubaa8\ub4e0 \ub178\ub4dc\ub97c \ud0d0\uc0c9\ud574\uc57c \ud558\ubbc0\ub85c \ube44\ub840\ud569\ub2c8\ub2e4. \uacf5\uac04 \ubcf5\uc7a1\ub3c4\ub294 O(H)\ub85c, H\ub294 \ud2b8\ub9ac\uc758 \ub192\uc774\ub97c \ub098\ud0c0\ub0c5\ub2c8\ub2e4. \uc774\ub294 \uc7ac\uadc0 \ud638\ucd9c \uc2a4\ud0dd\uc758 \uae4a\uc774\uc5d0 \ud574\ub2f9\ud569\ub2c8\ub2e4.<\/p>\n
      \uc608\uc81c \uc2e4\ud589<\/h2>\n
      \n        \/\/ \ud2b8\ub9ac \uc608\uc2dc \uc0dd\uc131 \ubc0f LCA \ucc3e\uae30\n        TreeNode root = new TreeNode(3);\n        root.Left = new TreeNode(5);\n        root.Right = new TreeNode(1);\n        root.Left.Left = new TreeNode(6);\n        root.Left.Right = new TreeNode(2);\n        root.Right.Left = new TreeNode(0);\n        root.Right.Right = new TreeNode(8);\n        root.Left.Right.Left = new TreeNode(7);\n        root.Left.Right.Right = new TreeNode(4);\n\n        Solution solution = new Solution();\n        TreeNode p = root.Left; \/\/ \ub178\ub4dc 5\n        TreeNode q = root.Left.Right; \/\/ \ub178\ub4dc 2\n        TreeNode lca = solution.LowestCommonAncestor(root, p, q);\n        Console.WriteLine($\"\ucd5c\uc18c \uacf5\ud1b5 \uc870\uc0c1: {lca.Value}\"); \/\/ 5 \ucd9c\ub825\n    <\/pre>\n
      \ub9c8\ubb34\ub9ac<\/h2>\n
      \uc624\ub298\uc740 C#\uc744 \uc0ac\uc6a9\ud558\uc5ec \ucd5c\uc18c \uacf5\ud1b5 \uc870\uc0c1 \ubb38\uc81c\ub97c \ud574\uacb0\ud558\ub294 \ubc29\ubc95\uc5d0 \ub300\ud574 \uc54c\uc544\ubcf4\uc558\uc2b5\ub2c8\ub2e4. \uc774 \ubb38\uc81c\ub294 \ub2e4\uc591\ud55c \uc54c\uace0\ub9ac\uc998 \ubb38\uc81c\ub4e4\uc744 \ud480\uae30 \uc704\ud55c \uae30\ucd08\uac00 \ub418\uba70, \ud2b8\ub9ac \uad6c\uc870\uc640 \uc7ac\uadc0\uc801 \uc0ac\uace0\ub97c \uc694\uad6c\ud569\ub2c8\ub2e4. \uc5f0\uc2b5\uc744 \ud1b5\ud574 \uc5ec\ub7ec\ubd84\uc758 \ucf54\ub529 \uc2e4\ub825\uc744 \ud5a5\uc0c1\uc2dc\ud0a4\uace0, \uc774\ubc88 \uae30\ud68c\uc5d0 C#\uc5d0 \ub300\ud55c \uc774\ud574\ub3c4\ub97c \ub192\uc77c \uc218 \uc788\uae30\ub97c \ubc14\ub78d\ub2c8\ub2e4.<\/p>\n