{"id":243,"date":"2024-01-13T15:48:22","date_gmt":"2024-01-13T07:48:22","guid":{"rendered":"https:\/\/wangqianming.top\/?p=243"},"modified":"2024-01-13T15:49:14","modified_gmt":"2024-01-13T07:49:14","slug":"%e5%bf%ab%e6%8e%92%e4%b8%8e%e5%a0%862-%e8%ae%a1%e6%95%b0%e6%8e%92%e5%ba%8f1","status":"publish","type":"post","link":"https:\/\/wangqianming.top\/index.php\/2024\/01\/13\/%e5%bf%ab%e6%8e%92%e4%b8%8e%e5%a0%862-%e8%ae%a1%e6%95%b0%e6%8e%92%e5%ba%8f1\/","title":{"rendered":"\u5feb\u6392\u4e0e\u58062 \u8ba1\u6570\u6392\u5e8f1"},"content":{"rendered":"

\u524dk\u4e2a\u9ad8\u9891\u5143\u7d20<\/h1>\n

\u7ed9\u4f60\u4e00\u4e2a\u6574\u6570\u6570\u7ec4 nums<\/code> \u548c\u4e00\u4e2a\u6574\u6570 k<\/code> \uff0c\u8bf7\u4f60\u8fd4\u56de\u5176\u4e2d\u51fa\u73b0\u9891\u7387\u524d k<\/code> \u9ad8\u7684\u5143\u7d20\u3002\u4f60\u53ef\u4ee5\u6309 \u4efb\u610f\u987a\u5e8f \u8fd4\u56de\u7b54\u6848\u3002<\/p>\n

\u793a\u4f8b 1:<\/strong><\/p>\n

\n

\u8f93\u5165: nums = [1,1,1,2,2,3], k = 2
\n\u8f93\u51fa: [1,2]<\/p>\n<\/blockquote>\n

\u793a\u4f8b 2:<\/strong><\/p>\n

\n

\u8f93\u5165: nums = [1], k = 1
\n\u8f93\u51fa: [1]<\/p>\n<\/blockquote>\n

\u5c0f\u6839\u5806<\/h2>\n

\u65b9\u6cd51\u662f\u4f7f\u7528\u5806\uff0c\u5148\u7edf\u8ba1\u6570\u91cf\u7136\u540e\u5efa\u4e00\u4e2a\u5c0f\u6839\u5806\uff0c\u5c0f\u6839\u5806\u7684\u6700\u5927\u8282\u70b9\u6570\u91cf\u662fk\uff0c\u4ecek\uff0b1\u4e2a\u5143\u7d20\u5f00\u59cb\uff0c\u8fdb\u6765\u7684\u5143\u7d20\u4e0e\u5c0f\u6839\u5806\u7684\u6839\u8282\u70b9\u8fdb\u884c\u6bd4\u8f83\uff0c\u82e5\u66f4\u5927\uff0c\u5219\u66ff\u6362\u3002<\/p>\n

class Solution {\n    public int[] topKFrequent(int[] nums, int k) {\n        Map<Integer, Integer> occurrences = new HashMap<Integer, Integer>();\n        for (int num : nums) {\n            occurrences.put(num, occurrences.getOrDefault(num, 0) + 1);\n        }\n\n        \/\/ int[] \u7684\u7b2c\u4e00\u4e2a\u5143\u7d20\u4ee3\u8868\u6570\u7ec4\u7684\u503c\uff0c\u7b2c\u4e8c\u4e2a\u5143\u7d20\u4ee3\u8868\u4e86\u8be5\u503c\u51fa\u73b0\u7684\u6b21\u6570\n        PriorityQueue<int[]> queue = new PriorityQueue<int[]>(new Comparator<int[]>() {\n            public int compare(int[] m, int[] n) {\n                return m[1] - n[1];\n            }\n        });\n        for (Map.Entry<Integer, Integer> entry : occurrences.entrySet()) {\n            int num = entry.getKey(), count = entry.getValue();\n            if (queue.size() == k) {\n                if (queue.peek()[1] < count) {\n                    queue.poll();\n                    queue.offer(new int[]{num, count});\n                }\n            } else {\n                queue.offer(new int[]{num, count});\n            }\n        }\n        int[] ret = new int[k];\n        for (int i = 0; i < k; ++i) {\n            ret[i] = queue.poll()[0];\n        }\n        return ret;\n    }\n}\n<\/code><\/pre>\n
\u5feb\u6392<\/h2>\n
\u57fa\u4e8e\u5feb\u901f\u6392\u5e8f\uff0c\u6bcf\u6b21\u9012\u5f52\u90fd\u53ef\u80fd\u4f1a\u51cf\u5c11\u4e0b\u4e00\u5c42\u7684\u6570\u91cf\uff0c\u5e73\u5747\u590d\u6742\u5ea6\u540c\u6837\u4e5f\u662fO(n)<\/code>.<\/p>\n
class Solution {\n    public int[] topKFrequent(int[] nums, int k) {\n        Map<Integer, Integer> occurrences = new HashMap<Integer, Integer>();\n        for (int num : nums) {\n            occurrences.put(num, occurrences.getOrDefault(num, 0) + 1);\n        }\n        \/\/ \u83b7\u53d6\u6bcf\u4e2a\u6570\u5b57\u51fa\u73b0\u6b21\u6570\n        List<int[]> values = new ArrayList<int[]>();\n        for (Map.Entry<Integer, Integer> entry : occurrences.entrySet()) {\n            int num = entry.getKey(), count = entry.getValue();\n            values.add(new int[]{num, count});\n        }\n        int[] ret = new int[k];\n        qsort(values, 0, values.size() - 1, ret, 0, k);\n        return ret;\n    }\n\n    public void qsort(List<int[]> values, int start, int end, int[] ret, int retIndex, int k) {\n        int picked = (int) (Math.random() * (end - start + 1)) + start;\n        Collections.swap(values, picked, start);\n\n        int pivot = values.get(start)[1];\n        int index = start;\n        for (int i = start + 1; i <= end; i++) {\n            \/\/ \u4f7f\u7528\u53cc\u6307\u9488\u628a\u4e0d\u5c0f\u4e8e\u57fa\u51c6\u503c\u7684\u5143\u7d20\u653e\u5230\u5de6\u8fb9\uff0c\n            \/\/ \u5c0f\u4e8e\u57fa\u51c6\u503c\u7684\u5143\u7d20\u653e\u5230\u53f3\u8fb9\n            if (values.get(i)[1] >= pivot) {\n                Collections.swap(values, index + 1, i);\n                index++;\n            }\n        }\n        Collections.swap(values, start, index);\n\n        if (k <= index - start) {\n            \/\/ \u524d k \u5927\u7684\u503c\u5728\u5de6\u4fa7\u7684\u5b50\u6570\u7ec4\u91cc\n            qsort(values, start, index - 1, ret, retIndex, k);\n        } else {\n            \/\/ \u524d k \u5927\u7684\u503c\u7b49\u4e8e\u5de6\u4fa7\u7684\u5b50\u6570\u7ec4\u5168\u90e8\u5143\u7d20\n            \/\/ \u52a0\u4e0a\u53f3\u4fa7\u5b50\u6570\u7ec4\u4e2d\u524d k - (index - start + 1) \u5927\u7684\u503c\n            for (int i = start; i <= index; i++) {\n                ret[retIndex++] = values.get(i)[0];\n            }\n            if (k > index - start + 1) {\n                qsort(values, index + 1, end, ret, retIndex, k - (index - start + 1));\n            }\n        }\n    }\n}\n<\/code><\/pre>\n
\u975e\u5e73\u51e1\u7684\u4e00\u79cd\u89e3\u6cd5\uff0c\u8ba1\u6570\u6392\u5e8f<\/h2>\n
\u8ba1\u6570\u6392\u5e8f\u76f4\u63a5\u4f7f\u7528\u5927\u91cf\u5197\u4f59\u7684\u7a7a\u95f4\u6765\u6362\u53d6\u65f6\u95f4\uff0c\u7ed9\u6bcf\u4e00\u4e2a\u53ef\u80fd\u51fa\u73b0\u7684\u503c\u90fd\u9884\u5148\u5206\u914d\u597d\u4f4d\u7f6e\u3002\u8fd9\u6837\u786e\u5b9e\u4f1a\u63d0\u901f\u4e0d\u5c11\uff0c\u4e0d\u8fc7\u8981\u614e\u91cd\u4f7f\u7528\u3002\u4e0b\u9762\u7684\u4f8b\u5b50\u76f4\u63a5\u4f7f\u7528\u4e86\u4e24\u6b21\u8ba1\u6570\u6392\u5e8f\uff0c\u901f\u5ea6\u6bd4\u4e0a\u9762\u7684\u65b9\u6cd5\u5feb\u4e8610\u500d\u3002<\/p>\n
class Solution {\n    public int[] topKFrequent(int[] nums, int k) {\n\n        int max = Integer.MIN_VALUE;\n        int min = Integer.MAX_VALUE;\n        for (int num : nums) {\n            if(num>max)\n                max = num;\n            if(num<min)\n                min = num;\n        }\n        int len = max - min + 1;\n        int[] k_v = new int[len];\n        for (int num : nums)\n            k_v[num - min]++;\n\n        int r_len = Integer.MIN_VALUE;\n        for(int num:k_v) {\n            if (num > r_len)\n                r_len = num;\n        }\n\n        ArrayList<Integer>[] reversedKV = new ArrayList[r_len + 1];\n        for (int i = 0; i < k_v.length; i++) {\n            if (k_v[i] > 0) {\n                ArrayList<Integer> o = reversedKV[k_v[i]];\n                if (o == null) {\n                    o = new ArrayList<>();\n                    reversedKV[k_v[i]] = o;\n                }\n                o.add(min + i);\n            }\n        }\n\n        int[] r_temp = new int[k];\n        int pos = 0;\n        for (int i = reversedKV.length - 1; i >= 0 && pos < k; i--) {\n            if (reversedKV[i] != null) {\n                for (int v : reversedKV[i]) {\n                    r_temp[pos++] = v;\n                    if (pos >= k)\n                        break;\n                }\n            }\n        }\n\n        return r_temp;\n\n    }\n\n}<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"
\u524dk\u4e2a\u9ad8\u9891\u5143\u7d20 \u7ed9\u4f60\u4e00\u4e2a\u6574\u6570\u6570\u7ec4 nums \u548c\u4e00\u4e2a\u6574\u6570 k \uff0c\u8bf7\u4f60\u8fd4\u56de\u5176\u4e2d\u51fa\u73b0\u9891\u7387\u524d k \u9ad8\u7684\u5143\u7d20\u3002\u4f60\u53ef\u4ee5\u6309 \u4efb\u610f\u987a\u5e8f \u8fd4\u56de\u7b54\u6848\u3002 …<\/p>","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[5,26,27,9,30],"class_list":["post-243","post","type-post","status-publish","format-standard","hentry","category-uncategorized","tag-java","tag-26","tag-27","tag-leetcode","tag-30"],"_links":{"self":[{"href":"https:\/\/wangqianming.top\/index.php\/wp-json\/wp\/v2\/posts\/243","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wangqianming.top\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wangqianming.top\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wangqianming.top\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/wangqianming.top\/index.php\/wp-json\/wp\/v2\/comments?post=243"}],"version-history":[{"count":2,"href":"https:\/\/wangqianming.top\/index.php\/wp-json\/wp\/v2\/posts\/243\/revisions"}],"predecessor-version":[{"id":246,"href":"https:\/\/wangqianming.top\/index.php\/wp-json\/wp\/v2\/posts\/243\/revisions\/246"}],"wp:attachment":[{"href":"https:\/\/wangqianming.top\/index.php\/wp-json\/wp\/v2\/media?parent=243"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wangqianming.top\/index.php\/wp-json\/wp\/v2\/categories?post=243"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wangqianming.top\/index.php\/wp-json\/wp\/v2\/tags?post=243"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}