{"id":2522,"date":"2018-03-21T00:13:03","date_gmt":"2018-03-20T16:13:03","guid":{"rendered":"https:\/\/boweihe.me\/?p=2522"},"modified":"2018-03-21T00:13:03","modified_gmt":"2018-03-20T16:13:03","slug":"leetcode-432-all-oone-data-structure","status":"publish","type":"post","link":"https:\/\/dayandcarrot.space\/?p=2522","title":{"rendered":"LeetCode 432. All O`one Data Structure"},"content":{"rendered":"

\u51e0\u4e07\u5e74\u6ca1\u505aLeetCode\u7684\u9898\u4e86\uff0c\u66f4\u65b0\u4e00\u4e0b\u3002
\nhttps:\/\/leetcode.com\/problems\/all-oone-data-structure\/description\/<\/a>
\n\u8fd9\u9053\u9898\u7684\u601d\u8def\u662f\u7528\u4e00\u4e2a\u53cc\u5411\u94fe\u8868(list)<\/strong>\u6765\u5b58\u50a8\u4e00\u4e2a\u4ee5value\u6392\u5e8f\u7684\u6570\u636e\u7ed3\u6784\uff0c\u4f7f\u7528\u54c8\u5e0c\u8868(unordered_map)<\/strong>\u6765\u5b58\u50a8key\u5230\u94fe\u8868iterator\u7684\u6620\u5c04\uff1a
\n\"\"
\n\u9700\u8981\u6ce8\u610f\u7279\u6b8a\u5904\u7406value=1\u7684Node\u7684\u60c5\u51b5\u3002
\n\u4ee3\u7801\u5199\u5f97\u6bd4\u8f83\u6bdb\u7cd9\uff0c\u4f46\u662f\u786e\u5b9e\u662fO(1)\u7684\u590d\u6742\u5ea6\uff0c\u5982\u679c\u8981\u4f18\u5316\u7684\u8bddmap\u7684\u63d2\u5165\u53ef\u4ee5\u7528emplace()\u4e4b\u7c7b\u7684\u3002
\n\u6ce8\u610f\uff1a\u9664\u4e86value=1\u7684\u8282\u70b9\uff0c\u5176\u4f59\u8282\u70b9\u7684keys\u4e3a\u7a7a\u7684\u65f6\u5019\u8981\u628a\u8be5\u8282\u70b9\u5220\u9664\u6389\uff0c\u5426\u5219getMaxKey()\u548cgetMinKey()\u5c31\u9700\u8981O(n)\u7684\u904d\u5386\u64cd\u4f5c\u4e86\u3002<\/p>\n

struct KvNode\n{\n    unordered_set<string> keys;\n    int value = 1;\n};\nclass AllOne {\nprivate:\n    list<KvNode> value_key;     \/\/ arranged by val in ascending order\n    using list_it_t = list<KvNode>::iterator;\n    unordered_map<string, list_it_t> val_map;\n    list_it_t init_node;    \/\/node with value one\npublic:\n    \/** Initialize your data structure here. *\/\n    AllOne() {\n        value_key.push_back(KvNode());\n        init_node = value_key.begin();\n    }\n    \/** Inserts a new key <Key> with value 1. Or increments an existing key by 1. *\/\n    void inc(const string& key) {\n        if (val_map.find(key) == val_map.end())\n        {\n            \/\/ `create' new node with value 1\n            init_node->keys.insert(key);\n            val_map[key] = init_node;\n        }\n        else\n        {\n            \/\/ find existing node\n            auto node_it = val_map[key];\n            node_it->keys.erase(key);   \/\/remove from current bulk\n            auto next_it = std::next(node_it, 1);\n            if (next_it == value_key.end() ||\n                 next_it->value != node_it->value + 1)\n            {\n                \/\/ no valid valued bulk, create one\n                KvNode node;\n                node.keys.insert(key);\n                node.value = node_it->value + 1;\n                val_map[key] = value_key.insert(next_it, node);\n            }\n            else\n            {\n                next_it->keys.insert(key);\n                val_map[key] = next_it;\n            }\n            if (node_it->keys.empty() && node_it->value != 1)\n            {\n                \/\/ remove node_it\n                value_key.erase(node_it);\n            }\n        }\n    }\n    \/** Decrements an existing key by 1. If Key's value is 1, remove it from the data structure. *\/\n    void dec(string key) {\n        auto it_val_map = val_map.find(key);\n        if (it_val_map == val_map.end())\n        {\n            \/\/ key does not exist\n            return;\n        }\n        else if (it_val_map->second->value == 1)\n        {\n            auto node_it = it_val_map->second;\n            node_it->keys.erase(key);\n            if (node_it->keys.empty() && node_it->value != 1)\n            {\n                value_key.erase(node_it);\n            }\n            val_map.erase(it_val_map);\n        }\n        else\n        {\n            auto node_it = it_val_map->second;\n            auto prev_it = std::prev(node_it, 1);\n            node_it->keys.erase(key);\n            if (prev_it->value != node_it->value - 1)\n            {\n                \/\/ create one\n                KvNode node;\n                node.keys.insert(key);\n                node.value = node_it->value - 1;\n                val_map[key] = value_key.insert(node_it, node);\n            }\n            else\n            {\n                prev_it->keys.insert(key);\n                val_map[key] = prev_it;\n            }\n            if (node_it->keys.empty() && node_it->value != 1)\n            {\n                value_key.erase(node_it);\n            }\n        }\n    }\n    \/** Returns one of the keys with maximal value. *\/\n    string getMaxKey() {\n        auto it_max = std::prev(value_key.end(), 1);\n        if (!it_max->keys.empty())\n            return *(it_max->keys.begin());\n        else\n            return \"\";\n    }\n    \/** Returns one of the keys with Minimal value. *\/\n    string getMinKey() {\n        auto it_min = value_key.begin();\n        if (it_min->value == 1 && it_min->keys.empty())\n            ++it_min;\n        if (it_min != value_key.end() && !it_min->keys.empty())\n            return *(it_min->keys.begin());\n        else\n            return \"\";\n    }\n};\n\/**\n * Your AllOne object will be instantiated and called as such:\n * AllOne obj = new AllOne();\n * obj.inc(key);\n * obj.dec(key);\n * string param_3 = obj.getMaxKey();\n * string param_4 = obj.getMinKey();\n *\/<\/pre>\n
 
\n 
\n <\/p>\n","protected":false},"excerpt":{"rendered":"
\u51e0\u4e07\u5e74\u6ca1\u505aLeetCode\u7684\u9898\u4e86\uff0c\u66f4\u65b0\u4e00\u4e0b\u3002 https:\/\/leetcode.com\/problems\/all-oone-data-structure\/description\/ \u8fd9\u9053\u9898\u7684\u601d\u8def\u662f\u7528\u4e00\u4e2a\u53cc\u5411\u94fe\u8868(list)\u6765\u5b58\u50a8\u4e00\u4e2a\u4ee5value\u6392\u5e8f\u7684\u6570\u636e\u7ed3\u6784\uff0c\u4f7f\u7528\u54c8\u5e0c\u8868(unordered_map)\u6765\u5b58\u50a8key\u5230\u94fe\u8868iterator\u7684\u6620\u5c04\uff1a \u9700\u8981\u6ce8\u610f\u7279\u6b8a\u5904\u7406value=1\u7684Node\u7684\u60c5\u51b5\u3002 \u4ee3\u7801\u5199\u5f97\u6bd4\u8f83\u6bdb\u7cd9\uff0c\u4f46\u662f\u786e\u5b9e\u662fO(1)\u7684\u590d\u6742\u5ea6\uff0c\u5982\u679c\u8981\u4f18\u5316\u7684\u8bddmap\u7684\u63d2\u5165\u53ef\u4ee5\u7528emplace()\u4e4b\u7c7b\u7684\u3002 \u6ce8\u610f\uff1a\u9664\u4e86value=1\u7684\u8282\u70b9\uff0c\u5176\u4f59\u8282\u70b9\u7684keys\u4e3a\u7a7a\u7684\u65f6\u5019\u8981\u628a\u8be5\u8282\u70b9\u5220\u9664\u6389\uff0c\u5426\u5219getMaxKey()\u548cgetMinKey()\u5c31\u9700\u8981O(n)\u7684\u904d\u5386\u64cd\u4f5c\u4e86\u3002 struct KvNode { unordered_set<string> keys; int value = 1; }; class AllOne { private: list<KvNode> value_key; \/\/ arranged by val in ascending order using list_it_t = list<KvNode>::iterator; unordered_map<string, list_it_t> val_map; list_it_t init_node; \/\/node with value one public: \/** Initialize your data structure here. *\/ AllOne() { value_key.push_back(KvNode()); init_node = […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[65],"class_list":["post-2522","post","type-post","status-publish","format-standard","hentry","category-study","tag-leetcode"],"_links":{"self":[{"href":"https:\/\/dayandcarrot.space\/index.php?rest_route=\/wp\/v2\/posts\/2522","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/dayandcarrot.space\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/dayandcarrot.space\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/dayandcarrot.space\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/dayandcarrot.space\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2522"}],"version-history":[{"count":0,"href":"https:\/\/dayandcarrot.space\/index.php?rest_route=\/wp\/v2\/posts\/2522\/revisions"}],"wp:attachment":[{"href":"https:\/\/dayandcarrot.space\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2522"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/dayandcarrot.space\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2522"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/dayandcarrot.space\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2522"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}