{"id":223124,"date":"2011-01-24T01:29:39","date_gmt":"2011-01-23T17:29:39","guid":{"rendered":"http:\/\/blog.yangzhe1991.org\/?p=223124"},"modified":"2014-03-14T19:09:14","modified_gmt":"2014-03-14T11:09:14","slug":"stl-sort%e6%ba%90%e7%a0%81%e5%89%96%e6%9e%90","status":"publish","type":"post","link":"https:\/\/yangzhe1991.org\/blog\/2011\/01\/stl-sort%e6%ba%90%e7%a0%81%e5%89%96%e6%9e%90\/","title":{"rendered":"stl sort\u6e90\u7801\u5256\u6790"},"content":{"rendered":"

\u4eca\u5929\u8bb2\u4e00\u4e0bSTL<algorithm>\u7684sort\u7684\u5b9e\u73b0<\/p>\n

\u5148\u76f4\u63a5\u4e0a\u4ee3\u7801\u3002\u56e0\u4e3a\u79cd\u79cd\u539f\u56e0\uff0c\u7528\u7684\u662fwindows\u7248codeblock\u5e26\u7684minGW\u63d0\u4f9b\u7684\u7248\u672c\uff0c\u5728c++\/bits\/stl_algo.h\u4e0b\u3002
\ntemplate<typename _RandomAccessIterator>
\ninline void
\nsort(_RandomAccessIterator __first, _RandomAccessIterator __last)
\n{
\ntypedef typename iterator_traits<_RandomAccessIterator>::value_type
\n <\/span>_ValueType;
\n\/\/ concept requirements
\n__glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
\n <\/span> _RandomAccessIterator>)
\n__glibcxx_function_requires(_LessThanComparableConcept<_ValueType>)
\n__glibcxx_requires_valid_range(__first, __last);
\nif (__first != __last)
\n <\/span>{
\n <\/span> std::__introsort_loop(__first, __last,std::__lg(__last – __first) * 2);
\n <\/span> std::__final_insertion_sort(__first, __last);
\n <\/span>}
\n}
\n\u9996\u5148\u8981\u660e\u786e\u51e0\u6761\uff0c\u51e1\u662f\u4e0b\u5212\u7ebf\u5f00\u5934\u7684\u53d8\u91cf\u3001\u51fd\u6570\u90fd\u662f\u5185\u90e8\u7684\u3001\u4e0d\u5f00\u653e\u7684\uff0c\u5c31\u662f\u8bf4STL\u7684\u7528\u6237\u4e0d\u4f1a\u77e5\u9053\u3002python\u76f4\u63a5\u7528\u53d8\u91cf\u524d\u52a0\u4e0b\u5212\u7ebf\u6765\u533a\u5206\u8bbf\u95ee\u6743\u9650\u3002
\ntypename\u53ef\u4ee5\u6362\u6210class\u4ec0\u4e48\u7684\uff0c\u5c31\u662f\u6b63\u5e38\u7684\u6a21\u7248\uff0cinline void\u4e0d\u89e3\u91ca\u3002\u53c2\u6570\u6709\u4e24\u4e2a\uff0c\u5c31\u662f\u9996\u5c3e\u8fed\u4ee3\u5668\uff0c_RandomAccessIterator\u662f\u6700\u9ad8\u7ea7\u7684\u8fed\u4ee3\u5668\uff0c\u53ef\u4ee5\u968f\u673a\u8bbf\u95ee\u3002\u4e5f\u90fd\u77e5\u9053\uff0csort\u5fc5\u987b\u662f\u53ef\u4ee5\u4efb\u610f\u8bbf\u95ee\u533a\u95f4\u5143\u7d20\u624d\u53ef\u4ee5\u7528\u7684\uff0c\u56e0\u800c\u94fe\u8868\u4e0d\u53ef\u4ee5\u3002\u94fe\u8868\u7684\u6392\u5e8f\u53ef\u4ee5\u770b\u8fd9\u4e2a<\/a>\u3002
\n\u5f53\u7136\u8fd8\u6709\u4e00\u4e2a\u7248\u672c\u662f\u53ef\u4ee5\u81ea\u5b9a\u4e49cmp\u51fd\u6570\u7684\uff0c\u5c31\u5728\u8fd9\u6bb5\u4ee3\u7801\u7684\u540e\u9762\uff0c\u7c7b\u4f3c\uff0c\u4e0d\u8bf4\u4e86\u3002
\nconcept requirements\u90a3\u4e09\u884c\u4ee3\u7801\uff0c\u524d\u4e24\u884c\u8fde\u5206\u53f7\u90fd\u6ca1\uff0c\u4e0d\u77e5\u9053\u5e72\u5417\u7528\u7684\u2026\u2026\u611f\u89c9\u5c31\u662f\u597d\u50cf\u662f\u58f0\u660e\u8fd9\u91cc\u8981\u7528\u5230c++lib\u91cc\u9762\u7684\u4ec0\u4e48\u4e1c\u897f\u5427\u3002\u4e0d\u8fc7\u8fd9\u4e5f\u4e0d\u803d\u8bef\u7406\u89e3sort\u4e86\u3002
\n\u7136\u540e\u5c31\u662f\u5f53\u533a\u95f4\u975e\u7a7a\u7684\u65f6\u5019\u5f00\u59cb\u6392\u5e8f\u3002\u6574\u4e2a\u6392\u5e8f\u5206\u4e3a\u4e24\u90e8\u5206\uff0cstd::__introsort_loop\u548cstd::__final_insertion_sort\uff0c\u540e\u8005\u5c31\u662f\u63d2\u5165\u6392\u5e8f\uff0c\u524d\u8005\u76f8\u5f53\u4e8eqsort\u7684\u6539\u8fdb\u7248\uff0c\u53ebintrosort\uff0c\u4e0d\u77e5\u9053\u8fd9\u4e2a\u4e2d\u6587\u540d\u6709\u6ca1\u6709\u6700\u666e\u904d\u7684\u7ffb\u8bd1\uff0c\u53cd\u6b63\u53eb\u5185X\u6392\u5e8f\uff0c\u5185\u4ec0\u4e48\u7684\u90fd\u6709\u3002
\n\u63d0introsort\u5f97\u5148\u8bf4\u6807\u51c6\u7684\u5feb\u6392\u3002\u6211\u4eec\u77e5\u9053\u5feb\u6392\u7684\u6838\u5fc3\u601d\u60f3\u5f88\u7b80\u5355\uff0c\u5c31\u662f\u627e\u4e2a\u6807\u5fd7\u7269\uff0c\u6bd4\u5b83\u5c0f\u653e\u5de6\u9762\uff0c\u6bd4\u5b83\u5927\u653e\u53f3\u9762\uff0c\u7136\u540e\u8fd9\u4e2a\u5143\u7d20\u5de6\u53f3\u4e24\u4e2a\u533a\u95f4\u5206\u522b\u518d\u6b21\u8fdb\u884c\u5feb\u6392\uff0c\u9012\u5f52\u8c03\u7528\u3002\u4f46\u5982\u679c\u9047\u5230\u7279\u6b8a\u60c5\u51b5\uff0c\u6bcf\u6b21\u9009\u7684\u90fd\u662f\u533a\u95f4\u91cc\u6700\u5c0f\u7684\u6216\u8005\u6700\u5927\u7684\uff0c\u90a3\u4e48\u533a\u95f4\u5c31\u6ca1\u6709\u5f97\u5230\u826f\u597d\u7684\u5212\u5206\uff0c\u6700\u574f\u60c5\u51b5\u662f\u9000\u5316\u5230\u5e73\u65b9\u7ea7\u3002\u4e8e\u662f\u5728\u53d6\u8fd9\u4e2a\u4e2d\u70b9\u5143\u7d20\u7684\u65b9\u6cd5\u4e0a\u8fdb\u884c\u5c3d\u53ef\u80fd\u7684\u4f18\u5316\u5c31\u662f\u5feb\u6392\u6700\u76f4\u63a5\u7684\u4f18\u5316\u65b9\u5f0f\u3002\u56e0\u4e3a\u6700\u574f\u60c5\u51b5\u662f\u5e73\u65b9\uff0c\u800c\u5e73\u5747\u671f\u671b\u662fnlogn\uff0c\u56e0\u6b64\u9700\u8981\u5c3d\u53ef\u80fd\u7684\u8ba9\u5b83\u4ee5\u5e73\u5747\u7684\u60c5\u51b5\u8fd0\u884c\u800c\u975e\u6700\u574f\u60c5\u51b5\u3002\u56e0\u6b64OIer\u90fd\u77e5\u9053\u968f\u673a\u5316\u5feb\u6392\uff0c\u5373\u4ecel\u5230r\u4e4b\u95f4\u53d6\u4e00\u4e2a\u968f\u673a\u6570\u4f5c\u4e3a\u4e2d\u95f4\u5143\u7d20\u7684\u7d22\u5f15\u4f4d\u7f6e\uff0c\u56e0\u4e3a\u662f\u968f\u673a\u7684\u6240\u4ee5\u6bcf\u6b21\u90fd\u53d6\u5230\u60b2\u5267\u7684\u6982\u7387\u4f1a\u5f88\u5c0f\u3002\u800c\u5728STL\u4e2d\uff08\u8d77\u7801\u662fGCC\u6240\u91c7\u7528\u7684\u7248\u672c\u4e2d\uff09\u91c7\u7528\u7684\u662f\u4ece\u9996\u3001\u4e2d\u70b9\u3001\u5c3e\u4e09\u4e2a\u5143\u7d20\u4e2d\u53d6\u4e2d\u503c\u6765\u5f97\u5230\u8fd9\u4e2a\u6807\u5fd7\u5143\u7d20\u3002\u81f3\u4e8e\u4e24\u8005\u54ea\u4e2a\u597d\u6211\u4e5f\u4e0d\u77e5\u9053\u3002\u4f46\u611f\u89c9\u5982\u679c\u662f\u7eaf\u5feb\u6392\u7684\u8bdd\u8fd8\u662f\u968f\u673a\u7684\u597d\uff0c\u9664\u975e\u751f\u6210\u968f\u673a\u6570\u4ee3\u4ef7\u5f88\u9ad8\uff1f\u4e0d\u8fc7\u56e0\u4e3aintrosort\u4f1a\u6709\u5404\u79cd\u4f18\u5316\u65b9\u6cd5\uff0c\u56e0\u6b64\u6807\u5fd7\u7269\u9009\u53d6\u5e26\u6765\u7684\u60b2\u5267\u4f1a\u5c3d\u53ef\u80fd\u964d\u4f4e\u3002
\nstd::__introsort_loop\u7684\u7b2c\u4e09\u4e2a\u53c2\u6570\u662fstd::__lg(__last – __first) * 2\u3002\u8fd9\u662f\u9650\u5236\u9012\u5f52\u6b21\u6570\u7684\u53c2\u6570\u3002lg\u51fd\u6570\u7684\u53c2\u6570\u5373\u4e3an\uff0c\u800c\u8fd4\u56de\u503c\u662f\u6ee1\u8db32^k<=n\u7684\u6700\u5927\u7684k\uff0c\u8fd9\u4e2a\u6570\u518d\u4e582\u5c31\u662f\u9012\u5f52\u6700\u5927\u6b21\u6570\u3002\u56e0\u4e3a\u4f20\u7edf\u7684qsort\u662f\u4e00\u76f4\u9012\u5f52\u5230\u53ea\u6709\u4e00\u4e24\u4e2a\u5143\u7d20\u7684\uff0c\u800c\u5f88\u6df1\u7684\u9012\u5f52\u9700\u8981\u5f88\u5927\u7684\u65f6\u95f4\u548c\u7a7a\u95f4\u5f00\u9500\uff0c\u56e0\u6b64introsort\u9996\u5148\u907f\u514d\u4e86\u9012\u5f52\u8fc7\u6df1\u9020\u6210\u7684\u6548\u7387\u7f3a\u5931\u3002
\n\u63a5\u4e0b\u6765\u770bstd::__introsort_loop\u7684\u4ee3\u7801
\n\/\/\/ This is a helper function for the sort routine.
\ntemplate<typename _RandomAccessIterator, typename _Size>
\nvoid
\n__introsort_loop(_RandomAccessIterator __first,
\n <\/span> _RandomAccessIterator __last,
\n <\/span> _Size __depth_limit)
\n{
\ntypedef typename iterator_traits<_RandomAccessIterator>::value_type <\/span>_ValueType;
\nwhile (__last – __first > int(_S_threshold))
\n <\/span>{
\n <\/span> if (__depth_limit == 0)
\n <\/span> {
\n <\/span> _GLIBCXX_STD_P::partial_sort(__first, __last, __last);
\n <\/span> return;
\n <\/span> }
\n <\/span> –__depth_limit;
\n <\/span> _RandomAccessIterator __cut =
\n <\/span> std::__unguarded_partition(__first, __last, _ValueType(std::__median(*__first,*(__first+ (__last- __first)\/ 2),*(__last – 1))));
\n <\/span> std::__introsort_loop(__cut, __last, __depth_limit);
\n <\/span> __last = __cut;
\n <\/span>}
\n}
\n\u524d\u51e0\u884c\u90fd\u6ca1\u4ec0\u4e48\u95ee\u9898\uff0c\u5148\u770b\u8fd9\u4e2a_S_threshold \u5176\u5b9a\u4e49\u4ee3\u7801\u5982\u4e0b\uff1a
\n\/**
\n* \u00a0@doctodo
\n* \u00a0This controls some aspect of the sort routines.
\n*\/
\nenum { _S_threshold = 16 };
\n\u4e0d\u77e5\u9053\u4e3a\u5565\u641e\u6210enmu\uff0c\u76f4\u63a5const int \u4e0d\u5c31\u5b8c\u4e86\u4e48\u2026\u2026\u603b\u4e4b\u77e5\u9053\u8fd9\u4e2a\u6570\u662f16\u5c31\u597d\u4e86\u3002\u610f\u601d\u5c31\u662f\uff0c\u5f53\u672c\u6b21\u9012\u5f52\u7684\u533a\u95f4\u5927\u5c0f\u4e0d\u523016\u7684\u65f6\u5019\uff0c\u5c31\u4e0d\u73a9\u4e86\u3002\u5f53\u7136\uff0c\u8fd9\u65f6\u5019\u80af\u5b9a\u8fd8\u6ca1\u6392\u597d\u5462\uff0c\u4f46\u522b\u5fd8\u4e86std::__introsort_loop\u540e\u9762\u8fd8\u6709\u00a0std::__final_insertion_sort\uff0c\u6b63\u5982\u5176\u540d\uff0c\u8d1f\u8d23\u9996\u5c3e\u3002
\n\u9996\u5148\u5c31\u662f\u5f53\u9012\u5f52\u5c42\u6570\u8fc7\u6df1\u7684\u65f6\u5019\uff0c\u8c03\u7528\u8fd9\u4e2a\u00a0_GLIBCXX_STD_P::partial_sort(__first, __last, __last)\uff0c\u5176\u4ee3\u7801\u5982\u4e0b\uff1a
\ntemplate<typename _RandomAccessIterator>
\ninline void
\npartial_sort(_RandomAccessIterator __first,
\n <\/span> _RandomAccessIterator __middle,
\n <\/span> _RandomAccessIterator __last)
\n{
\ntypedef typename iterator_traits<_RandomAccessIterator>::value_type
\n <\/span>_ValueType;
\n\/\/ concept requirements
\n__glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
\n <\/span> _RandomAccessIterator>)
\n__glibcxx_function_requires(_LessThanComparableConcept<_ValueType>)
\n__glibcxx_requires_valid_range(__first, __middle);
\n__glibcxx_requires_valid_range(__middle, __last);
\nstd::__heap_select(__first, __middle, __last);
\nstd::sort_heap(__first, __middle);
\n}
\n\u8fd9\u662f\u4e00\u4e2a\u6bd4\u8f83\u86cb\u75bc\u7684\u51fd\u6570\uff0c\u76ee\u7684\u662f\u8ba9\u4e00\u4e2a\u5e8f\u5217\u6bd4\u8f83\u5c0f\u7684\u90e8\u5206\u6709\u5e8f\u7684\u5728first-middle\uff0c\u6bd4\u8f83\u5927\u7684\u90e8\u5206\u968f\u610f\u7684\u5728middle-last.\u5c31\u662f\u8bf4\u524d\u534a\u7aef\u6709\u5e8f\uff0c\u540e\u534a\u6bb5\u65e0\u5e8f\uff0c\u4f46\u662f\u524d\u534a\u6bb5\u90fd\u6bd4\u540e\u534a\u6bb5\u5c0f\u3002\u56e0\u4e3a\u4e0d\u5e26__\u6240\u4ee5\u8fd9\u4e2a\u4e5f\u662f\u53ef\u4ee5\u76f4\u63a5\u7528\u7684\u3002\u4ece\u4e0b\u9762\u5b9e\u73b0\u53ef\u4ee5\u770b\u51fa\uff0c\u5148\u7528\u4e00\u4e2a\u5185\u90e8\u7684std::__heap_select\u53bb\u7528\u5806\u6765\u9009\u62e9\u5c0f\u7684\u5728\u524d\u5927\u7684\u5728\u540e\uff0c\u7136\u540e\u4e00\u4e2a\u6807\u51c6\u7684\u5806\u6392\u6392\u5e8f\u524d\u534a\u6bb5\u3002\u9009\u62e9\u7684\u51fd\u6570\u4ee3\u7801\u4e0d\u53d1\u4e86\uff0c\u4f46\u53ef\u4ee5\u544a\u8bc9\u5927\u5bb6\u5b9e\u73b0\u65b9\u6cd5\u662f\u5148\u8ba9\u524d\u534a\u6bb5\u5143\u7d20\u5f62\u6210\u4e00\u4e2a\u5806\uff08\u5e94\u8be5\u662f\u6700\u5927\u5806\uff09\uff0c\u7136\u540efor\u5faa\u73af\u5206\u522b\u8ddf\u540e\u534a\u6bb5\u7684\u6bcf\u4e00\u4e2a\u5143\u7d20\u6bd4\u8f83\uff0c\u4e00\u65e6\u67d0\u4e2a\u5143\u7d20\u6bd4\u73b0\u5728\u5806\u91cc\u7684\u6839\u90e8\uff08\u6700\u5927\u7684\uff09\u8981\u5c0f\uff0c\u5c31\u4ea4\u6362\u4e24\u8005\u4f4d\u7f6e\uff0c\u8ba9\u5806\u91cc\u7684\u53bb\u5916\u9762\uff0c\u5916\u9762\u90a3\u4e2a\u8fdb\u5806\uff0c\u7136\u540e\u8c03\u6574\u5143\u7d20\u4fdd\u6301\u6700\u5927\u5806\u7279\u6027\u3002\u56e0\u4e3a\u5806\u9996\uff08__first\uff09\u6c38\u8fdc\u662f\u524d\u534a\u6bb5\u6700\u5927\u7684\uff0c\u56e0\u6b64\u4e0d\u80fd\u6709\u4efb\u4f55\u4e00\u4e2a\u540e\u534a\u6bb5\u7684\u5143\u7d20\u6bd4\u524d\u9762\u7684\u5927\uff0c\u800c\u4ea4\u6362\u4e4b\u540e\u5806\u7684\u6839\u80af\u5b9a\u4f1a\u53d8\u5c0f\uff0c\u56e0\u6b64\u540e\u534a\u6bb5\u4e4b\u524d\u6bd4\u8f83\u8fc7\u7684\u5143\u7d20\u80af\u5b9a\u4f1a\u6bd4\u65b0\u7684\u5927\uff08\u4e0d\u7136\u4e4b\u524d\u5c31\u6362\u8fdb\u53bb\u4e86\uff09\uff0c\u56e0\u800c\u4e00\u904d\u626b\u63cf\u4e4b\u540e\u5c31\u4fdd\u8bc1\u524d\u9762\u662f\u7684\u90fd\u6bd4\u540e\u9762\u5c0f\uff0c\u8fd8\u80fd\u4fdd\u8bc1\u524d\u9762\u662f\u5806\uff0c\u4e8e\u662f\u76f4\u63a5sort_heap\u5806\u6392\u3002\u8fd9\u4e2a\u51fd\u6570\u8981\u6c42\u5df2\u7ecf\u662f\u5806\u3002
\n\u5806\u662f\u4ec0\u4e48\u5462\u2026\u2026\u8fd9\u4e2a\u5c31\u5148\u4e0d\u8bb2\u5427\uff0c\u4e0d\u77e5\u9053\u5c31google\uff0c\u6211\u89c9\u5f97\u5927\u591a\u6570\u80fd\u770b\u5230\u73b0\u5728\u7684\u4eba\u90fd\u77e5\u9053\u4ec0\u4e48\u662f\u5806\u4e86\u3002
\n\u4f46\u8fd9\u90fd\u4e0d\u662f\u95ee\u9898\uff0c\u6700\u5927\u7684\u95ee\u9898\u662f\uff0c\u4e3a\u4ec0\u4e48\u5f53\u9012\u5f52\u8fc7\u6df1\u7684\u65f6\u5019\u8981\u8c03\u7528_GLIBCXX_STD_P::partial_sort(__first, __last, __last)\uff1f\u53ef\u4ee5\u770b\u5230\u628a\u4e2d\u70b9\u8ddflast\u91cd\u5408\uff0c\u5c31\u662f\u8bf4\u8ba9\u4ed6\u8c03\u7528__heap_select\u8ba9\u6574\u4e2a\u533a\u95f4\u53d8\u6210\u5806\uff0c\u7136\u540e\u8c03\u7528sort_heap\u8fdb\u884c\u5806\u6392\u3002\u6211\u9664\u4e86\u86cb\u75bc\u4e4b\u5916\u60f3\u4e0d\u5230\u4efb\u4f55\u4e00\u4e2a\u89e3\u91ca\u53ef\u4ee5\u8bf4\u660e\u4e3a\u4f55\u8fd9\u4e2a\u5199\u4ee3\u7801\u7684\u4eba\u5982\u6b64\u8c03\u7528\u800c\u4e0d\u662f\u76f4\u63a5make_heap(__first, __last)\u518dsort_heap(__first, __last)\u2026\u2026
\n\u597d\u4e86\u4e0d\u7ea0\u7ed3\u4e86\uff0c\u56de\u5230\u4e4b\u524d\u7684if (__depth_limit == 0)\u4e0a\u3002\u5df2\u7ecf\u660e\u767d\u4e86\uff0c\u6298\u817e\u5927\u534a\u5708\u5c31\u662f\u60f3\u8ba9introsort\u5728\u9012\u5f52\u8fc7\u6df1\u800c\u5143\u7d20\u7531\u4e0d\u5c0f\u4e8e16\u7684\u65f6\u5019\u76f4\u63a5\u6362\u6210\u5806\u6392\u6765\u5b9e\u73b0\u3002
\n\u4e3a\u4ec0\u4e48\u4e0d\u76f4\u63a5\u7528\u5806\u6392\uff1f\u6211\u4eec\u8981\u770b\u5806\u6392\u7684\u539f\u7406\uff0c\u5148\u662f\u4e00\u4e2a\u626b\u63cf\u5efa\u5806\uff0c\u7136\u540e\u6bcf\u6b21\u53d6\u51fa\u6700\u5927\u5143\u7d20\u90fd\u9700\u8981\u8fdb\u884c\u53ef\u80fd\u7684\u91cd\u65b0\u8c03\u6574\uff0c\u56e0\u6b64\u867d\u7136\u5806\u6392\u4e5f\u662fnlogn\u7684\u7b97\u6cd5\u4f46\u662f\u7531\u4e8e\u9700\u8981\u5927\u91cf\u7684\u5143\u7d20\u4ea4\u6362\uff0c\u5e38\u6570\u5f88\u5927\uff0c\u800c\u5feb\u6392\u7684\u5e38\u6570\u5f88\u5c0f\uff0c\u56e0\u6b64\u6548\u7387\u66f4\u9ad8\u3002\u5f53\u7136\u5728\u9012\u5f52\u8fc7\u6df1\u7684\u65f6\u5019\u5feb\u6392\u4e5f\u6bd4\u8f83\u60b2\u5267\uff0c\u7406\u8bba\u548c\u5b9e\u8df5\u8868\u660e\u8fd9\u65f6\u5019\u7528\u5806\u6392\u662f\u66f4\u5feb\u7684\u3002
\n\u63a5\u4e0b\u6765\u770b\u4ee3\u7801\uff0c\u6211\u4eec\u4f1a\u53d1\u73b0\u9012\u5f52\u8c03\u7528\u53ea\u8c03\u7528\u4e86\u540e\u534a\u6bb5\u3002\u901a\u5e38\u6211\u4eec\u5199\u7684\u9012\u5f52\u80af\u5b9a\u6700\u540e\u4e24\u884c\u5e94\u8be5\u662fqsort(l,m-1)\u548cqsort(m+1,r)\u4e4b\u7c7b\u7684\u3002\u8fd9\u91cc\u53ea\u8c03\u7528\u4e00\u4e2a\u3002\u4f46\u8c03\u7528\u8fc7\u540e\uff0c\u65b0\u7684last\u53d8\u6210\u4e86\u539f\u6765\u7684cut\uff0c\u5c31\u662f\u8bf4while\u5faa\u73af\u7684\u4e0b\u4e00\u6b21\u5c31\u662f\u524d\u4e00\u6b21\u7684\u5de6\u534a\u6bb5\u3002\u8fd9\u4e0d\u5f71\u54cd\u9012\u5f52\u6df1\u5ea6\uff0c\u56e0\u4e3a\u5728\u8fd9\u6b21\u5faa\u73af\u8c03\u7528\u7684\u9012\u5f52\u6df1\u5ea6\u9650\u5236\u5df2\u7ecf-1\uff0c\u56e0\u6b64\u5269\u4e0b\u7684\u5de6\u534a\u6bb5\u548c\u9012\u5f52\u8fdb\u53bb\u7684\u6709\u534a\u6bb5\u662f\u540c\u6837\u7684\u5269\u4f59\u6df1\u5ea6\u3002
\ncut\u662f\u53c2\u7167\u70b9\u7684\u8fed\u4ee3\u5668\u3002\u901a\u8fc7__unguarded_partition\u51fd\u6570\u8fd4\u56de\u3002\u4ed6\u6709\u4e09\u4e2a\u53c2\u6570\uff0c\u9996\u3001\u5c3e\u4ee5\u53ca\u8fd0\u884c\u524d\u9009\u53d6\u7684\u53c2\u7167\u70b9\u7684\u4f4d\u7f6e\u3002\u53ef\u4ee5\u770b\u51faSTL\u7684\u5b9e\u73b0\u5e76\u6ca1\u6709\u91c7\u7528\u968f\u673a\uff0c\u800c\u662f\u53d6\u9996\u3001\u4e2d\u3001\u5c3e\u4e09\u4e2a\u5143\u7d20\u5927\u5c0f\u6392\u5728\u4e2d\u95f4\u7684\u90a3\u4e00\u4e2a\u3002\u7136\u540e\u6b64\u51fd\u6570\u5c06\u6bd4\u53c2\u7167\u5236\u5c0f\u7684\u653e\u5de6\u9762\uff0c\u5927\u7684\u653e\u53f3\u9762\uff0c\u53c2\u7167\u503c\u5728\u4e2d\u95f4\uff0c\u5e76\u8fd4\u56de\u8be5\u503c\u7684\u8fed\u4ee3\u5668\u3002
\n\u4ee5\u4e0a\u5c31\u662fintrosort\u51fd\u6570\u7684\u5168\u90e8\u5185\u5bb9\u3002\u4f46\u6211\u4e0d\u77e5\u9053\u5b66\u672f\u4e0a\u7684\u6807\u51c6introsort\u662f\u5982\u4f55\u5b9e\u73b0\u3002\u4f46\u80af\u5b9a\u8fd8\u662f\u5feb\u6392\u548c\u5806\u6392\u914d\u5408\uff0c\u4e0d\u8fc7\u4e0d\u77e5\u9053\u90a3\u4e2a16\u540e\u8fdb\u884cfinal\u5728\u4e0d\u5728\u6807\u51c6\u7684introsort\u91cc\u9762\u3002
\n\u7136\u540e\u5c31\u662fstd::__final_insertion_sort(__first, __last)\u4e86\uff0c\u5df2\u7ecf\u77e5\u9053\uff0c\u73b0\u5728\u7684\u533a\u95f4\u662f\u4e00\u4e2a\u51e0\u4e4e\u5df2\u7ecf\u6392\u597d\u7684\u533a\u95f4\uff0c\u53ea\u4e0d\u8fc7\u5f53\u67d0\u4e2a\u5b50\u533a\u95f4\u5c0f\u4e8e16\u7684\u65f6\u5019\uff0c\u662f\u6bd4\u8f83\u4e71\u7684\uff0c\u5728\u6574\u4f53\u4e0a\u662f\u6709\u5e8f\u7684\u3002\u90a3\u5c31\u770b\u770b\u5982\u4f55\u8fdb\u884c\u6536\u5c3e\u5de5\u4f5c\uff1a
\n\/\/\/ This is a helper function for the sort routine.
\ntemplate<typename _RandomAccessIterator>
\nvoid
\n__final_insertion_sort(_RandomAccessIterator __first,
\n <\/span> _RandomAccessIterator __last)
\n{
\nif (__last – __first > int(_S_threshold))
\n <\/span>{
\n <\/span> std::__insertion_sort(__first, __first + int(_S_threshold));
\n <\/span> std::__unguarded_insertion_sort(__first + int(_S_threshold), __last);
\n <\/span>}
\nelse
\n <\/span>std::__insertion_sort(__first, __last);
\n}
\n\u4ece\u540d\u5b57\u5c31\u77e5\u9053\u80af\u5b9a\u662f\u63d2\u5165\u6392\u5e8f\u4e86\u3002\u5982\u679c\u533a\u95f4\u5c0f\u4e8e16\u5c31\u662f\u4e00\u4e2a\u6734\u7d20\u7684\u63d2\u5165\u6392\u5e8f\u3002\u5982\u679c\u5927\u4e8e16\uff0c\u90a3\u4e48\u524d16\u4e2a\u63d2\u5165\u6392\u5e8f\uff0c\u540e\u9762\u7684std::__unguarded_insertion_sort\u3002\u8fd9\u4e2a\u51fd\u6570\u5c31\u662f\u4e00\u4e2afor\u5faa\u73af\uff0c\u6bcf\u6b21\u8ba9\u7b2ci\u4e2a\u5143\u7d20\u8ddf\u524di-1\u4e2a\u5143\u7d20\u6328\u4e2a\u6bd4\uff0c\u4f9d\u6b21\u4ecei-1\u52301\u626b\u63cf\u4e00\u65e6i\u6bd4\u90a3\u4e2a\u6570\u5c0f\u628a\u90a3\u4e2a\u6570\u5f80\u540e\u8bfa\uff0c\u5982\u679ci\u6bd4\u90a3\u4e2a\u6570\u5927\u5c31\u4e0d\u632a\u4e86\u3002\u6734\u7d20\u7684__insertion_sort\u662f\u4e00\u4e2afor\u5faa\u73af\u6bcf\u6b21\u8ba9\u524di\u4e2a\u5143\u7d20\u901a\u8fc7\u63d2\u5165\u6392\u5e8f\u4fdd\u6301\u6709\u5e8f\uff0c\u6240\u4ee5\u6bcf\u6b21\u7b2ci\u4e2a\u5143\u7d20\u6765\u4e86\u5c31\u63d2\u5230\u8be5\u63d2\u7684\u5730\u65b9\u5c31\u76f4\u63a5\u8fdb\u53bb\u4e86\u3002\u6709\u4e2a\u4f18\u5316\u662f\u5982\u679c\u7b2ci\u4e2a\u5143\u7d20\u6bd4\u7b2c\u4e00\u4e2a\u5c0f\uff0c\u5c31\u4e0d\u626b\u63cf\u76f4\u63a5\u8ba91~i-1\u5206\u522b\u5f80\u53f3\uff0c\u7136\u540e\u7b2ci\u4e2a\u53bb\u7b2c1\u4e2a\u3002
\n\u56e0\u6b64\uff0c__insertion_sort\u9002\u5408\u5b8c\u5168\u6253\u4e71\u7684\u521d\u59cb\u6392\u5e8f\u3002\u56e0\u4e3a\u5b9e\u73b0\u65b9\u6cd5\u5c31\u662f\u5e73\u65b9\u7ea7\u7684\u3002\u4f46std::__unguarded_insertion_sort\u5efa\u7acb\u5728\u4e2d\u4e2a\u533a\u95f4\u5df2\u7ecf\u6bd4\u8f83\u6709\u5e8f\u7684\u60c5\u51b5\u4e0b\uff0c\u5373\u4f7f\u662f\u63d2\u5165\u6392\u5e8f\uff0c\u6bcf\u6b21\u9700\u8981\u8c03\u6574\u7684\u8fde\u7eed\u7a7a\u95f4\u4e00\u5b9a\u4e0d\u4f1a\u8d85\u8fc716\uff08\u56e0\u4e3a\u5927\u4e8e16\u7684\u533a\u95f4\u4e00\u5b9a\u662f\u90e8\u5206\u6709\u5e8f\u7684\uff0c\u4e0d\u4f1a\u8d8a\u754c\uff09\u3002\u63d2\u5165\u6392\u5e8f\u7684\u4e3b\u8981\u65f6\u95f4\u90fd\u7528\u5728\u4e86\u632a\u4e1c\u897f\u4e0a\uff0c\u5982\u679c\u4fdd\u8bc1\u632a\u7684\u4e1c\u897f\u5f88\u5c11\uff0c\u90a3\u4e48\u6548\u7387\u5c31\u975e\u5e38\u9ad8\u4e86\u3002\u800c\u524d\u671f\u7684introsort\u5c31\u662f\u4fdd\u8bc1\u8fd9\u4e00\u70b9\u3002
\n\u4ee5\u4e0a\u5c31\u662fSTL\u4e2dsort\u7b97\u6cd5\u7684\u5b9e\u73b0\uff0c\u53ef\u4ee5\u8bf4\u6b64\u7b97\u6cd5\u7684\u9ad8\u6548\u5c24\u5176\u662f\u76f8\u5bf9\u4e8e\u5355\u7eafqsort\u7684\u9ad8\u6548\u662f\u6e90\u4e8eintrosort\u8fd9\u79cd\u7ec4\u5408\u6392\u5e8f\u7b97\u6cd5\u7684\u4f18\u52bf\u3002\u81f3\u4e8e\u4ee3\u7801\u662f\u5426\u5199\u7684\u9ad8\u6548\u5c31\u4e0d\u77e5\u9053\u4e86\u3002\u4e0d\u8fc7\u53ef\u4ee5\u80af\u5b9a\u7684\u662f\u5806\u6392\u90a3\u6bb5\u662f\u7edd\u5bf9\u7684\u86cb\u75bc\uff0c\u800c\u4e8c\u5206\u9012\u5f52\u90a3\u6bb5\u90a3\u4e48\u5199\u8ddf\u666e\u901a\u7684\u4e24\u4e2a\u9012\u5f52\u54ea\u4e2a\u597d\u4e5f\u4e0d\u77e5\u9053\u3002\u5176\u5b9eSTL\u672c\u8eab\u8bbe\u8ba1\u7684\u521d\u8877\u867d\u7136\u8003\u8651\u5230\u4e86\u6548\u7387\u4f46\u66f4\u4e3b\u8981\u7684\u9996\u5148\u8981\u4fdd\u6301\u7edf\u4e00\u6027\u3002\u56e0\u6b64\u67d0\u4e9b\u65f6\u5019\u751a\u81f3\u5f88\u591a\u65f6\u5019STL\u7684\u65f6\u95f4\u6548\u7387\u5e76\u4e0d\u4e00\u5b9a\u5c31\u6bd4\u6211\u4eec\u81ea\u5df1\u5199\u7684\u597d\u3002\u6211\u4eec\u81ea\u5df1\u5199\u7684\u4ee3\u7801\u56e0\u4e3a \u4e0d\u9700\u8981\u8003\u8651\u66f4\u591a\u7684\u6269\u5c55\u6027\uff0c\u53ef\u80fd\u5c31\u6bd4STL\u7684\u5feb\u90a3\u4e48\u4e00\u70b9\u70b9\u3002\u52a0\u4e0aSTL\u7531\u4e8e\u79cd\u79cd\u539f\u56e0\uff0c\u8bbe\u8ba1\u7684\u5f88\u597d\u4f46\u5b9e\u73b0\u4e4b\u540e\u4f1a\u6709\u4e9b\u4e0d\u8db3\u3002\u603b\u4e4bSTL\u4e0d\u662f\u4e07\u80fd\u7684\uff0c\u66f4\u4e0d\u662f\u5b8c\u7f8e\u7684\uff0c\u4ed6\u6700\u91cd\u8981\u7684\u662f\u65b9\u4fbf\uff0c\u8282\u7ea6\u7a0b\u5e8f\u5458\u7684\u65f6\u95f4\u3002\u63d0\u4f9b\u4e86\u4e00\u4e2a\u51e0\u4e4e\u6700\u597d\u7684\u4ee3\u7801\u590d\u7528\u65b9\u6848\u3002
\n\u5f53\u7136\uff0c\u5bf9\u4e8eACMer\u8fd8\u6709\u4ee5\u540e\u7684OIer\u6765\u8bf4\uff0c\u4ed6\u7701\u4e86\u4e0d\u5c11\u505a\u9898\u65f6\u7684\u529f\u592b\uff0c\u5f53\u7136\u4e5f\u8ba9\u6211\u4eec\u5bf9\u5f88\u591a\u7b97\u6cd5\u7814\u7a76\u4e0d\u591f\u6df1\u5165\u3002<\/p>\n

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