{"id":102,"date":"2023-12-09T11:09:45","date_gmt":"2023-12-09T03:09:45","guid":{"rendered":"https:\/\/blog.zwdblog.online\/?p=102"},"modified":"2023-12-20T17:08:11","modified_gmt":"2023-12-20T09:08:11","slug":"fifo%e5%85%88%e8%bf%9b%e5%85%88%e5%87%ba%ef%bc%89%e3%80%81lru%ef%bc%88%e6%9c%80%e5%b0%91%e4%bd%bf%e7%94%a8%ef%bc%89%e3%80%81opt%ef%bc%88%e6%9c%80%e4%bd%b3%e7%bd%ae%e6%8d%a2%ef%bc%89%e7%ae%97%e6%b3%95","status":"publish","type":"post","link":"https:\/\/blog.zwdblog.online\/index.php\/2023\/12\/09\/fifo%e5%85%88%e8%bf%9b%e5%85%88%e5%87%ba%ef%bc%89%e3%80%81lru%ef%bc%88%e6%9c%80%e5%b0%91%e4%bd%bf%e7%94%a8%ef%bc%89%e3%80%81opt%ef%bc%88%e6%9c%80%e4%bd%b3%e7%bd%ae%e6%8d%a2%ef%bc%89%e7%ae%97%e6%b3%95\/","title":{"rendered":"FIFO(\u5148\u8fdb\u5148\u51fa\uff09\u3001LRU\uff08\u6700\u5c11\u4f7f\u7528\uff09\u3001OPT\uff08\u6700\u4f73\u7f6e\u6362\uff09\u7b97\u6cd5"},"content":{"rendered":"\n<p>\u4e00\u3001\u5b9e\u73b0\u8981\u6c42<\/p>\n\n\n\n<p>\uff081\uff09\u7cfb\u7edf\u91c7\u7528\u56fa\u5b9a\u5206\u914d\u3001\u5c40\u90e8\u7f6e\u6362\u7684\u7b56\u7565<br>\uff082)  \u5206\u914d\u7ed9\u8fdb\u7a0b\u7684\u7269\u7406\u5757\u6570\u5728\u7a0b\u5e8f\u4e2d\u53ef\u9009\uff1a3\u6216\u80054<br>\uff083\uff09\u7cfb\u7edf\u968f\u673a\u4ea7\u751f\u9875\u9762\u8bbf\u95ee\u5e8f\u5217\u5730\u5740\uff0c\u5e8f\u5217\u957f\u5ea6\u4e3a20\uff0c<br>\uff084\uff09\u8fd0\u884c\u65f6\uff0c\u5b9e\u73b0\u4e86\u8f93\u5165\u5206\u914d\u7ed9\u8fdb\u7a0b\u7684\u7269\u7406\u5757\u6570\uff0c\u7cfb\u7edf\u8f93\u51fa\u968f\u673a\u9875\u8bbf\u95ee\u5e8f\u5217\u3001\u7269\u7406\u5757\u88c5\u5165\u9875\u9762\u60c5\u51b5\uff0c\u5e76\u6700\u7ec8\u6253\u5370\u51fa\u7f3a\u9875\u6b21\u6570\u4e0e\u7f3a\u9875\u7387<\/p>\n\n\n\n<p>\u4e8c\u3001\u7b97\u6cd5\u7684\u4ecb\u7ecd<\/p>\n\n\n\n<p>\u5f53\u6d89\u53ca\u5230\u9875\u9762\u7f6e\u6362\u7b97\u6cd5\u65f6\uff0c\u4e09\u79cd\u4e3b\u8981\u7684\u7b97\u6cd5\u662fFIFO\uff08\u5148\u8fdb\u5148\u51fa\uff09\u3001LRU\uff08\u6700\u8fd1\u6700\u5c11\u4f7f\u7528\uff09\u548cOPT\uff08\u6700\u4f73\u7f6e\u6362\uff09\u3002<\/p>\n\n\n\n<p>     1\u3001<strong>FIFO\uff08\u5148\u8fdb\u5148\u51fa\uff09<\/strong>\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u57fa\u672c\u601d\u60f3\u662f\u6309\u7167\u9875\u9762\u6700\u65e9\u8fdb\u5165\u5185\u5b58\u7684\u987a\u5e8f\u8fdb\u884c\u7f6e\u6362\u3002<\/li>\n\n\n\n<li>\u6bcf\u6b21\u65b0\u7684\u9875\u9762\u6765\u5230\u5185\u5b58\u65f6\uff0c\u5c06\u6700\u65e9\u8fdb\u5165\u5185\u5b58\u7684\u9875\u9762\u66ff\u6362\u51fa\u53bb\u3002<\/li>\n\n\n\n<li>\u7f3a\u70b9\u662f\u5b83\u5e76\u4e0d\u8003\u8651\u9875\u9762\u7684\u8bbf\u95ee\u9891\u7387\u6216\u6a21\u5f0f\uff0c\u53ef\u80fd\u4f1a\u56e0\u4e3a\u957f\u65f6\u95f4\u9a7b\u7559\u5185\u5b58\u7684\u9875\u9762\u5bfc\u81f4\u6027\u80fd\u4e0b\u964d\u3002<\/li>\n<\/ul>\n\n\n\n<p>    2\u3001<strong>LRU\uff08\u6700\u8fd1\u6700\u5c11\u4f7f\u7528\uff09<\/strong>\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u57fa\u4e8e\u201c\u6700\u8fd1\u6700\u5c11\u4f7f\u7528\u201d\u7684\u539f\u5219\u8fdb\u884c\u7f6e\u6362\u3002<\/li>\n\n\n\n<li>\u6bcf\u6b21\u66ff\u6362\u65f6\u9009\u62e9\u6700\u8fd1\u6700\u5c11\u88ab\u4f7f\u7528\u7684\u9875\u9762\uff0c\u5f53\u8bbf\u95ee\u5230\u7684\u5e8f\u5217\u4e0d\u5728\u7269\u7406\u5757\u4e2d\u65f6\uff0c\u52a0\u5230\u7269\u7406\u5757\uff08\u5b57\u5178\uff09\u672b\u5c3e\uff0c\u628a\u6700\u65e9\u4f7f\u7528\u7684\u5934\uff08\u7269\u7406\u5757\u7684\u7b2c\u4e00\u4f4d\uff09pop\u6389\uff0c\u5f53\u8bbf\u95ee\u7684\u5e8f\u5217\u5728\u7269\u7406\u5757\u4e2d\u65f6\uff0c\u76f4\u63a5\u66ff\u6362\u6389\u8be5\u9875\u9762\uff0c\u628a\u65b0\u7684\u4e00\u6837\u7684\u9875\u9762\u52a0\u5230\u7269\u7406\u5757\uff08\u5b57\u5178\uff09\u672b\u5c3e\u3002<\/li>\n\n\n\n<li>\u901a\u8fc7\u7ef4\u62a4\u9875\u9762\u4f7f\u7528\u7684\u987a\u5e8f\uff0c\u53ef\u4ee5\u6709\u6548\u5730\u4fdd\u7559\u7ecf\u5e38\u88ab\u4f7f\u7528\u7684\u9875\u9762\uff0c\u63d0\u9ad8\u7f13\u5b58\u547d\u4e2d\u7387\u3002<\/li>\n\n\n\n<li>\u5b9e\u73b0\u4e0a\u53ef\u80fd\u9700\u8981\u7ef4\u62a4\u4e00\u4e2a\u8bbf\u95ee\u8bb0\u5f55\u6216\u8005\u8bb0\u5f55\u9875\u9762\u6700\u8fd1\u4f7f\u7528\u7684\u65f6\u95f4\u6233\u3002<\/li>\n<\/ul>\n\n\n\n<p>    3\u3001<strong>OPT\uff08\u6700\u4f73\u7f6e\u6362\uff09<\/strong>\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>OPT\u662f\u7406\u8bba\u4e0a\u7684\u6700\u4f18\u7b97\u6cd5\uff0c\u5b83\u5229\u7528\u672a\u6765\u9875\u9762\u8bbf\u95ee\u7684\u4fe1\u606f\u8fdb\u884c\u7f6e\u6362\u3002<\/li>\n\n\n\n<li>\u5728\u6bcf\u6b21\u7f6e\u6362\u65f6\uff0c\u9009\u62e9\u672a\u6765\u6700\u957f\u65f6\u95f4\u4e0d\u88ab\u8bbf\u95ee\u7684\u9875\u9762\u8fdb\u884c\u66ff\u6362\u3002\uff08\u5373\u4e0d\u5728\u672a\u6765\u5b57\u5178\u4e2d\u7684\u9875\u9762\uff09<\/li>\n\n\n\n<li>\u4e3a\u4e86\u5b9e\u73b0\u8fd9\u4e2a\u7b97\u6cd5\uff0c\u9700\u8981\u9884\u77e5\u672a\u6765\u9875\u9762\u8bbf\u95ee\u7684\u60c5\u51b5\uff0c\u8fd9\u5728\u5b9e\u9645\u4e2d\u901a\u5e38\u662f\u4e0d\u53ef\u80fd\u7684\uff0c\u56e0\u6b64OPT\u901a\u5e38\u88ab\u7528\u4f5c\u8bc4\u4f30\u5176\u4ed6\u7b97\u6cd5\u7684\u6027\u80fd\u4e0a\u9650\u3002<\/li>\n<\/ul>\n\n\n\n<p>\u5176\u6b21\uff0cFIFO\u7b80\u5355\u6613\u5b9e\u73b0\u4f46\u6027\u80fd\u4e00\u822c\uff0cLRU\u8f83\u4e3a\u590d\u6742\u4f46\u5728\u4e00\u5b9a\u7a0b\u5ea6\u4e0a\u63d0\u9ad8\u4e86\u6027\u80fd\uff0c\u800cOPT\u5219\u662f\u7406\u8bba\u4e0a\u7684\u6700\u4f73\u65b9\u6848\uff0c\u4f46\u5b9e\u9645\u5e94\u7528\u53d7\u9650\u4e8e\u672a\u6765\u9875\u9762\u8bbf\u95ee\u60c5\u51b5\u7684\u4e0d\u53ef\u77e5\u6027\u3002\u5728\u5b9e\u9645\u7cfb\u7edf\u4e2d\uff0c\u5f80\u5f80\u4f1a\u6839\u636e\u5177\u4f53\u7684\u573a\u666f\u548c\u9700\u6c42\u9009\u62e9\u9002\u5408\u7684\u7b97\u6cd5\u3002<\/p>\n\n\n\n<p>\u4e09\u3001\u7a0b\u5e8f\u6240\u4f7f\u7528\u6570\u636e\u7ed3\u6784\u53ca\u5176\u8bf4\u660e<\/p>\n\n\n\n<p>1. \u5217\u8868\uff08List\uff09\uff1a<\/p>\n\n\n\n<p>&nbsp;&nbsp;&nbsp;&#8211; `frames` \u5728 FIFO \u548c OPT \u7b97\u6cd5\u4e2d\u7528\u4e8e\u6a21\u62df\u9875\u9762\u5e27\u3002<\/p>\n\n\n\n<p>&nbsp;&nbsp;&nbsp;&#8211; `page_sequence` \u7528\u4e8e\u5b58\u50a8\u751f\u6210\u7684\u968f\u673a\u9875\u9762\u8bbf\u95ee\u5e8f\u5217\u3002<\/p>\n\n\n\n<p>2. \u5b57\u5178\uff08Dictionary\uff09\uff1a<\/p>\n\n\n\n<p>&nbsp;&nbsp;&nbsp;&#8211; `future_pages` \u5728 OPT \u7b97\u6cd5\u4e2d\u7528\u4e8e\u5b58\u50a8\u9884\u6d4b\u672a\u6765\u9875\u9762\u8bbf\u95ee\u7684\u4fe1\u606f\u3002<\/p>\n\n\n\n<p>&nbsp;&nbsp;&nbsp;&#8211; `self.frames` \u5728 LRU \u7c7b\u4e2d\u4f7f\u7528 `OrderedDict` \u6a21\u62df\u9875\u9762\u5e27\u3002<\/p>\n\n\n\n<p>3. OrderedDict\uff1a<\/p>\n\n\n\n<p>&nbsp;&nbsp;&nbsp;&#8211; `self.frames` \u5728 LRU \u7c7b\u4e2d\u4f7f\u7528 `OrderedDict` \u6765\u5b9e\u73b0LRU\u9875\u9762\u7f6e\u6362\u7b97\u6cd5\uff0c\u4fdd\u6301\u9875\u9762\u8bbf\u95ee\u7684\u987a\u5e8f\u3002<\/p>\n\n\n\n<p>\u56db\u3001\u7a0b\u5e8f\u8fd0\u884c\u622a\u56fe\u4ee5\u53ca\u8bf4\u660e<\/p>\n\n\n\n<p>\u7269\u7406\u5757\u6570\u4e0e\u9875\u9762\u8bbf\u95ee\u5e8f\u5217:<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"136\" src=\"https:\/\/blog.zwdblog.online\/wp-content\/uploads\/2023\/12\/image-11-1024x136.png\" alt=\"\u7b2c\u4e00\u5f20\" class=\"wp-image-127\" srcset=\"https:\/\/blog.zwdblog.online\/wp-content\/uploads\/2023\/12\/image-11-1024x136.png 1024w, https:\/\/blog.zwdblog.online\/wp-content\/uploads\/2023\/12\/image-11-300x40.png 300w, https:\/\/blog.zwdblog.online\/wp-content\/uploads\/2023\/12\/image-11-768x102.png 768w, https:\/\/blog.zwdblog.online\/wp-content\/uploads\/2023\/12\/image-11.png 1050w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<p>\u53ef\u4ee5\u770b\u5230\u8f93\u5165\u7684\u5206\u914d\u7ed9\u8fdb\u7a0b\u7684\u7269\u7406\u5757\u6570\u4e3a3<\/p>\n\n\n\n<p>\u540c\u65f6\u968f\u673a\u9875\u9762\u8bbf\u95ee\u5e8f\u5217\uff1a [6, 7, 3, 4, 9, 0, 7, 4, 7, 7, 5, 9, 1, 2, 9, 0, 9, 7, 6, 2]\u957f\u5ea6\u4e3a20<\/p>\n\n\n\n<p>1\u3001FIFO\u7b97\u6cd5\u6267\u884c<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"780\" height=\"820\" src=\"https:\/\/blog.zwdblog.online\/wp-content\/uploads\/2023\/12\/image-12.png\" alt=\"FIFO\u7b97\u6cd5\u6267\u884c\u56fe\" class=\"wp-image-128\" srcset=\"https:\/\/blog.zwdblog.online\/wp-content\/uploads\/2023\/12\/image-12.png 780w, https:\/\/blog.zwdblog.online\/wp-content\/uploads\/2023\/12\/image-12-285x300.png 285w, https:\/\/blog.zwdblog.online\/wp-content\/uploads\/2023\/12\/image-12-768x807.png 768w\" sizes=\"auto, (max-width: 780px) 100vw, 780px\" \/><\/figure>\n\n\n\n<p>\u7b97\u6cd5\u8bf4\u660e\uff1a<br>   \uff081\uff09\u6309\u7167\u9875\u9762\u6700\u5148\u8fdb\u5165\u9875\u9762\u5e27\u7684\u987a\u5e8f\u8fdb\u884c\u9875\u9762\u7f6e\u6362\u3002<br>   \uff082\uff09\u9875\u9762\u8bbf\u95ee\u5e8f\u5217\u4ee5\u53ca\u7269\u7406\u5757\u88c5\u5165\u60c5\u51b5\u7684\u6f14\u53d8\u8fc7\u7a0b\u5c55\u793a\u4e86\u6bcf\u6b21\u9875\u9762\u8bbf\u95ee\u65f6\u7269\u7406\u5757\u7684\u53d8\u5316\u60c5\u51b5\u3002<br>   \uff083\uff09\u5f53\u9875\u9762\u5e27\u5df2\u6ee1\u65f6\uff0cFIFO\u7b97\u6cd5\u4f1a\u5c06\u6700\u5148\u8fdb\u5165\u9875\u9762\u5e27\u7684\u9875\u9762\u66ff\u6362\u51fa\u53bb\uff0c\u5373\u4f7f\u8be5\u9875\u9762\u5728\u672a\u6765\u8fd8\u4f1a\u88ab\u8bbf\u95ee\u3002<br>   \uff084\uff09\u7f3a\u9875\u6b21\u6570\u8868\u793a\u9700\u8981\u4ece\u78c1\u76d8\u4e2d\u83b7\u53d6\u7684\u9875\u9762\u6570\u91cf\uff0c\u7f3a\u9875\u7387\u5219\u8868\u793a\u9875\u9762\u7f6e\u6362\u5e26\u6765\u7684\u6027\u80fd\u635f\u5931\u3002<br>   \uff085\uff09\u5728\u8fd9\u4e2a\u60c5\u51b5\u4e0b\uff0c\u968f\u673a\u9875\u9762\u8bbf\u95ee\u5e8f\u5217\u548cFIFO\u7b97\u6cd5\u7684\u7ec4\u5408\u5bfc\u81f4\u4e86\u8f83\u9ad8\u7684\u7f3a\u9875\u7387\u3002\u8fd9\u662f\u56e0\u4e3aFIFO\u7b97\u6cd5\u4ec5\u8003\u8651\u4e86\u9875\u9762\u8fdb\u5165\u9875\u9762\u5e27\u7684\u5148\u540e\u987a\u5e8f\uff0c\u800c\u6ca1\u6709\u8003\u8651\u5230\u9875\u9762\u7684\u8bbf\u95ee\u9891\u7387\u6216\u6a21\u5f0f\uff0c\u5bfc\u81f4\u4e86\u8f83\u9ad8\u7684\u9875\u9762\u7f3a\u5931\u7387\u3002<\/p>\n\n\n\n<p>2\u3001LRU\u7b97\u6cd5<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"759\" height=\"822\" src=\"https:\/\/blog.zwdblog.online\/wp-content\/uploads\/2023\/12\/image-16.png\" alt=\"LRU\u7b97\u6cd5\u6267\u884c\u56fe\" class=\"wp-image-132\" srcset=\"https:\/\/blog.zwdblog.online\/wp-content\/uploads\/2023\/12\/image-16.png 759w, https:\/\/blog.zwdblog.online\/wp-content\/uploads\/2023\/12\/image-16-277x300.png 277w\" sizes=\"auto, (max-width: 759px) 100vw, 759px\" \/><\/figure>\n\n\n\n<p>\u7b97\u6cd5\u8bf4\u660e\uff1a<\/p>\n\n\n\n<p>LRU\u7b97\u6cd5\u6839\u636e\u9875\u9762\u6700\u8fd1\u7684\u8bbf\u95ee\u60c5\u51b5\u6765\u51b3\u5b9a\u9875\u9762\u7f6e\u6362\uff0c\u6700\u8fd1\u6700\u5c11\u4f7f\u7528\u7684\u9875\u9762\u4f1a\u88ab\u7f6e\u6362\u51fa\u53bb\u3002\u9875\u9762\u8bbf\u95ee\u5e8f\u5217\u4ee5\u53ca\u7269\u7406\u5757\u88c5\u5165\u60c5\u51b5\u7684\u53d8\u5316\u5c55\u793a\u4e86\u6bcf\u6b21\u9875\u9762\u8bbf\u95ee\u65f6\u7269\u7406\u5757\u7684\u53d8\u5316\u60c5\u51b5\u3002\u5f53\u9875\u9762\u5e27\u5df2\u6ee1\u65f6\uff0cLRU\u7b97\u6cd5\u4f1a\u6839\u636e\u9875\u9762\u7684\u6700\u8fd1\u4f7f\u7528\u60c5\u51b5\u9009\u62e9\u6700\u8fd1\u6700\u5c11\u4f7f\u7528\u7684\u9875\u9762\u8fdb\u884c\u7f6e\u6362\u3002\u5982\u5f53\u524d\u9875\u9762\u8bbf\u95ee\u5e8f\u5217: 0 \u7269\u7406\u5757\u88c5\u5165\u60c5\u51b5: [4, 9, 0]\uff0c\u518d\u4e4b\u540e\u5f53\u524d\u9875\u9762\u8bbf\u95ee\u5e8f\u5217: 7 \u7684\u60c5\u51b5\u4e2d\uff0c7\u6ca1\u6709\u5728\u7269\u7406\u5757\u4e2d\uff0c\u90a3\u4e48\u4e0b\u4e00\u4e2a\u7269\u7406\u5757\u88c5\u5165\u60c5\u51b5\u5c31\u4e3a[9, 0, 7]\uff0c\u628a4pop\u51fa\u53bb\u4e86\uff0c\u56e0\u4e3a\u4ece\u5f53\u524d\u8bbf\u95ee\u503c7\u5f80\u524d\u770b\uff0c4\u7684\u9996\u6b21\u51fa\u73b0\u7684\u4f4d\u7f6e\u662f\u6700\u65e9\u7684\uff0c\u6240\u4ee5\u662f\u6700\u8fd1\u6700\u65e9\u4f7f\u7528\u8fc7\uff0c\u6240\u4ee5pop\u6389\uff0c\u518d\u5982\u5f53\u524d\u9875\u9762\u8bbf\u95ee\u5e8f\u5217: 0 \u7269\u7406\u5757\u88c5\u5165\u60c5\u51b5: [2, 9, 0]\uff0c\u4e0b\u4e00\u4e2a\u9875\u9762\u8bbf\u95ee\u5e8f\u5217: 9 \u4e2d\uff0c9\u5df2\u7ecf\u5728\u7269\u7406\u5757\u4e2d\uff0c\u8bc1\u660e\u4e4b\u524d\u8bbf\u95ee\u8fc7\uff0c\u90a3\u4e48\u5c31pop\u6389\u8be5\u9875\u628a\u65b0\u7684\u9875\u9762\u52a0\u5165\uff0c\u4e3a[2, 0, 9]\uff0c\u4f60\u4e5f\u53ef\u4ee5\u901a\u8fc7\u6539\u53d8\u4ee3\u7801\u53d8\u6210\u662f\u66ff\u6362\u8be5\u9875\u800c\u4e0d\u662fpop\u51fa\u53bb\u52a0\u5c3e\u5df4\u3002<\/p>\n\n\n\n<p>3\u3001OPT\u7b97\u6cd5<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"771\" height=\"821\" src=\"https:\/\/blog.zwdblog.online\/wp-content\/uploads\/2023\/12\/image-14.png\" alt=\"OPT\u7b97\u6cd5\u6267\u884c\u56fe\" class=\"wp-image-130\" srcset=\"https:\/\/blog.zwdblog.online\/wp-content\/uploads\/2023\/12\/image-14.png 771w, https:\/\/blog.zwdblog.online\/wp-content\/uploads\/2023\/12\/image-14-282x300.png 282w, https:\/\/blog.zwdblog.online\/wp-content\/uploads\/2023\/12\/image-14-768x818.png 768w\" sizes=\"auto, (max-width: 771px) 100vw, 771px\" \/><\/figure>\n\n\n\n<p>\u7b97\u6cd5\u8bf4\u660e\uff1a<\/p>\n\n\n\n<p>\u4e0a\u8ff0\u6bcf\u4e2a\u9875\u9762\u88ab\u8bbf\u95ee\u65f6\uff0cOPT\u7b97\u6cd5\u90fd\u4f1a\u5c1d\u8bd5\u9884\u6d4b\u672a\u6765\u7684\u9875\u9762\u8bbf\u95ee\u987a\u5e8f\uff0c\u5e76\u636e\u6b64\u9009\u62e9\u8981\u66ff\u6362\u7684\u9875\u9762\u3002\u7136\u800c\uff0cOPT\u7b97\u6cd5\u9700\u8981\u672a\u6765\u9875\u9762\u8bbf\u95ee\u5e8f\u5217\u7684\u5b8c\u6574\u4fe1\u606f\uff0c\u56e0\u6b64\u5728\u5b9e\u9645\u5e94\u7528\u4e2d\u65e0\u6cd5\u83b7\u5f97\u3002\u5728\u8be5\u4f8b\u5b50\u4e2d\uff0c\u7531\u4e8e\u6ca1\u6709\u672a\u6765\u9875\u9762\u8bbf\u95ee\u5e8f\u5217\u7684\u4fe1\u606f\uff0c\u7b97\u6cd5\u53ea\u80fd\u57fa\u4e8e\u5f53\u524d\u5df2\u77e5\u7684\u4fe1\u606f\u8fdb\u884c\u9875\u9762\u66ff\u6362\uff0c\u6240\u4ee5\u7f3a\u9875\u6b21\u6570\u662f12\u6b21\uff0c\u7f3a\u9875\u7387\u4e3a60%\uff0c\u5982\u5728\u6267\u884c\u56fe\u4e2d\u5f53\u524d\u9875\u9762\u8bbf\u95ee\u5e8f\u5217\uff1a9\uff0c\u7269\u7406\u5757\u88c5\u5165\u60c5\u51b5[9, 7, 4]\uff1b\u5f53\u524d\u9875\u9762\u8bbf\u95ee\u5e8f\u5217\uff1a0\uff0c\u7269\u7406\u5757\u88c5\u5165\u60c5\u51b5[0, 7, 4]\uff1b\u6211\u4eec\u53ef\u4ee5\u770b\u5230\u5f53\u8bbf\u95ee\u52300\u65f6\uff0c\u4ece\u5f53\u524d0\u4f4d\u7f6e\u5f80\u540e\u770b\uff0c9\u51fa\u73b0\u7684\u7b2c\u4e00\u4e2a\u4f4d\u7f6e\u662f\u6700\u8fdc\u7684\uff0c\u5373\u5728\u5f88\u957f\u4e00\u6bb5\u65f6\u95f4\u51859\u4e0d\u4f1a\u88ab\u8bbf\u95ee\uff0c\u6240\u4ee5\u66ff\u6362\u6389\uff0c\u4ee5\u6b64\u7c7b\u63a8\u3002<\/p>\n\n\n\n<p>\u4e94\u3001\u4e09\u79cd\u7b97\u6cd5\u4f18\u7f3a\u70b9\u6bd4\u8f83<\/p>\n\n\n\n<p><strong>FIFO\uff08\u5148\u8fdb\u5148\u51fa\uff09<\/strong><\/p>\n\n\n\n<p>\u4f18\u70b9\uff1a<\/p>\n\n\n\n<p>1. \u5b9e\u73b0\u7b80\u5355\uff0c\u6613\u4e8e\u7406\u89e3\u548c\u90e8\u7f72\u3002<\/p>\n\n\n\n<p>2. \u5bf9\u4e8e\u67d0\u4e9b\u9875\u9762\u8bbf\u95ee\u6a21\u5f0f\uff0c\u8868\u73b0\u826f\u597d\u3002<\/p>\n\n\n\n<p>\u7f3a\u70b9\uff1a<\/p>\n\n\n\n<p>1. \u53ef\u80fd\u5bfc\u81f4Belady\u73b0\u8c61\uff0c\u5373\u589e\u52a0\u7269\u7406\u5757\u6570\u53cd\u800c\u4f1a\u589e\u52a0\u7f3a\u9875\u7387\u3002<\/p>\n\n\n\n<p>2. \u4e0d\u8003\u8651\u9875\u9762\u8bbf\u95ee\u9891\u7387\u548c\u65f6\u95f4\u987a\u5e8f\uff0c\u4e0d\u80fd\u9002\u5e94\u67d0\u4e9b\u590d\u6742\u7684\u8bbf\u95ee\u6a21\u5f0f\u3002<\/p>\n\n\n\n<p><strong>LRU\uff08\u6700\u8fd1\u6700\u5c11\u4f7f\u7528\uff09<\/strong><\/p>\n\n\n\n<p>\u4f18\u70b9\uff1a<\/p>\n\n\n\n<p>1. \u5728\u67d0\u4e9b\u573a\u666f\u4e0b\u80fd\u591f\u6709\u6548\u51cf\u5c11\u7f3a\u9875\u7387\u3002<\/p>\n\n\n\n<p>2. \u901a\u5e38\u60c5\u51b5\u4e0b\u80fd\u8f83\u597d\u5730\u6a21\u62df\u51fa\u8f83\u5c11\u8bbf\u95ee\u7684\u9875\u9762\u8fdb\u884c\u7f6e\u6362\u3002<\/p>\n\n\n\n<p>\u7f3a\u70b9\uff1a<\/p>\n\n\n\n<p>1. \u5b9e\u73b0\u7a0d\u5fae\u590d\u6742\u4e00\u4e9b\uff0c\u9700\u8981\u8bb0\u5f55\u9875\u9762\u8bbf\u95ee\u65f6\u95f4\u6216\u8005\u9891\u7387\u3002<\/p>\n\n\n\n<p>2. \u53ef\u80fd\u5728\u67d0\u4e9b\u60c5\u51b5\u4e0b\u65e0\u6cd5\u5f88\u597d\u5730\u6a21\u62df\u51fa\u6700\u4f73\u7684\u9875\u9762\u7f6e\u6362\u3002<\/p>\n\n\n\n<p><strong>OPT\uff08\u6700\u4f73\u7f6e\u6362\uff09<\/strong><\/p>\n\n\n\n<p>\u4f18\u70b9\uff1a<\/p>\n\n\n\n<p>1. \u7b97\u6cd5\u7406\u8bba\u4e0a\u80fd\u591f\u8fbe\u5230\u6700\u4f73\u6548\u679c\uff0c\u5373\u6700\u5c11\u7684\u7f3a\u9875\u7387\u3002<\/p>\n\n\n\n<p>2. \u4f5c\u4e3a\u4e00\u79cd\u7406\u60f3\u5316\u7b97\u6cd5\uff0c\u63d0\u4f9b\u4e86\u8861\u91cf\u5176\u4ed6\u7b97\u6cd5\u6027\u80fd\u7684\u6807\u51c6\u3002<\/p>\n\n\n\n<p>\u7f3a\u70b9\uff1a<\/p>\n\n\n\n<p>1. \u9700\u8981\u5bf9\u672a\u6765\u6240\u6709\u9875\u9762\u8bbf\u95ee\u8fdb\u884c\u9884\u6d4b\uff0c\u8fd9\u5728\u5b9e\u9645\u4e2d\u51e0\u4e4e\u662f\u4e0d\u53ef\u80fd\u505a\u5230\u7684\u3002<\/p>\n\n\n\n<p>2. \u7b97\u6cd5\u65e0\u6cd5\u5e94\u5bf9\u5b9e\u9645\u573a\u666f\u4e2d\u7684\u52a8\u6001\u53d8\u5316\u548c\u672a\u77e5\u7684\u9875\u9762\u8bbf\u95ee\u6a21\u5f0f\uff0c\u4ec5\u4f5c\u4e3a\u6027\u80fd\u7684\u4e00\u4e2a\u7406\u8bba\u4e0a\u7684\u4e0a\u9650\u3002<\/p>\n\n\n\n<p><strong>\u7cfb\u7edf\u6bd4\u8f83\uff1a<\/strong><\/p>\n\n\n\n<p>1. \u6027\u80fd\uff1a OPT\u7406\u8bba\u4e0a\u6700\u4f18\uff0c\u4f46\u5b9e\u9645\u65e0\u6cd5\u5b9e\u73b0\u3002LRU\u5728\u5f88\u591a\u60c5\u51b5\u4e0b\u8868\u73b0\u826f\u597d\uff0c\u5c24\u5176\u662f\u5bf9\u4e8e\u5c40\u90e8\u6027\u8f83\u5f3a\u7684\u8bbf\u95ee\u6a21\u5f0f\u3002FIFO\u7b80\u5355\u6613\u5b9e\u73b0\uff0c\u4f46\u5728\u67d0\u4e9b\u60c5\u51b5\u4e0b\u7f3a\u9875\u7387\u53ef\u80fd\u8f83\u9ad8\u3002<\/p>\n\n\n\n<p>2. \u590d\u6742\u5ea6\uff1a FIFO\u662f\u6700\u7b80\u5355\u7684\uff0cLRU\u7a0d\u590d\u6742\u4e00\u4e9b\u9700\u8981\u8bb0\u5f55\u8bbf\u95ee\u65f6\u95f4\u6216\u9891\u7387\uff0cOPT\u5219\u662f\u7406\u8bba\u4e0a\u6700\u590d\u6742\u7684\uff0c\u9700\u8981\u5bf9\u672a\u6765\u9875\u9762\u8bbf\u95ee\u8fdb\u884c\u9884\u6d4b\u3002<\/p>\n\n\n\n<p>3. \u5b9e\u7528\u6027\uff1a \u5728\u5b9e\u9645\u5e94\u7528\u4e2d\uff0c\u5e38\u7528\u7684\u662fLRU\u7b97\u6cd5\uff0c\u56e0\u4e3a\u5b83\u5728\u6027\u80fd\u548c\u5b9e\u73b0\u590d\u6742\u5ea6\u4e4b\u95f4\u6709\u4e00\u4e2a\u826f\u597d\u7684\u5e73\u8861\uff0c\u800c\u4e14\u5728\u8bb8\u591a\u573a\u666f\u4e2d\u8868\u73b0\u4e0d\u9519\u3002<\/p>\n\n\n\n<p>\u516d\u3001\u9644\u5168\u90e8\u4ee3\u7801<\/p>\n\n\n\n<pre class=\"wp-block-code\" style=\"font-size:17px\"><code>import random\nfrom collections import OrderedDict\n\n#FIFO\u9875\u9762\u7f6e\u6362\uff08\u5148\u8fdb\u5148\u51fa\uff09\ndef fifo(page_reference_string, num_frames):\n    frames = &#91;]\n    page_faults = 0  #\u7f3a\u9875\u6570\u91cf\uff08\u5373\u6240\u9700\u7684\u9875\u9762\u4e0d\u5728\u5185\u5b58\u4e2d\uff09\n\n    print(\"\\nFIFO\u9875\u9762\u66ff\u6362\u7b97\u6cd5\\n\")\n\n    for page in page_reference_string:\n        if page not in frames:\n            if len(frames) &lt; num_frames:\n                frames.append(page)\n            else:\n                frames.pop(0)\n                frames.append(page)\n            page_faults += 1\n\n        print(\"\u5f53\u524d\u9875\u9762\u8bbf\u95ee\u5e8f\u5217: {}\uff0c\u7269\u7406\u5757\u88c5\u5165\u60c5\u51b5: {}\".format(page, frames))\n\n    return page_faults\n\n#LRU\u9875\u9762\u7f6e\u6362\uff08\u6700\u5c11\u4f7f\u7528\uff09\nclass LRU:\n    def __init__(self, num_frames):\n        self.num_frames = num_frames\n        self.frames = OrderedDict() #OrderedDict\u7528\u4e8e\u6a21\u62df\u9875\u9762\u5e27\uff08\u5373\u5185\u5b58\u4e2d\u7684\u9875\u9762\uff09\uff0c\u5b58\u952e\u503c\u5bf9\u3002\n        self.page_faults = 0  #\u7f3a\u5931\u9875\u9875\u6570\n\n    def reference_page(self, page):\n        if page not in self.frames:\n            if len(self.frames) &gt;= self.num_frames:\n                self.frames.popitem(last=False)  #\u8c03\u7528opitem() \u65b9\u6cd5\u7528\u4e8e\u79fb\u9664\u5b57\u5178\u4e2d\u7684\u6700\u65e9\u7684\u4e00\u9879\uff08last = false\uff09\uff0c\u5982\u679clast = true\uff0c\u90a3\u4e48\u79fb\u9664\u6700\u540e\u4e00\u9879\n            self.frames&#91;page] = None #\u5c06\u65b0\u5f15\u7528\u7684\u9875\u9762\u52a0\u5165\u9875\u9762\u5e27\u4e2d\uff0c\u5373\u52a0\u5230\u5b57\u5178\u672b\u5c3e\uff0c\u503c\u4e3aNone(page\u662f\u952e\uff0cNone\u662f\u503c)\n            self.page_faults += 1\n        else:\n            self.frames.pop(page)\n            self.frames&#91;page] = None\n    \n    def display_frames(self,page):\n        print(\"\u5f53\u524d\u9875\u9762\u8bbf\u95ee\u5e8f\u5217: {} \u7269\u7406\u5757\u88c5\u5165\u60c5\u51b5: {}\".format(page,list(self.frames.keys())))\n\n    def get_page_faults(self):\n        return self.page_faults\n\n#OPT\u9875\u9762\u7f6e\u6362\uff08\u6700\u4f73\u7f6e\u6362\uff09\n# \u83b7\u53d6\u63a5\u4e0b\u6765\u4e0d\u4f1a\u4f7f\u7528\u6216\u6700\u8fdc\u4f1a\u4f7f\u7528\u7684\u9875\u9762\ndef get_future_pages(pages, current_index):\n    future_pages = {}\n    # \u4ece\u5f53\u524d\u4f4d\u7f6e\u5f80\u540e\u904d\u5386\u9875\u9762\u5e8f\u5217\n    for i in range(current_index + 1, len(pages)):\n        # \u5982\u679c\u9875\u9762\u4e0d\u5728\u9884\u6d4b\u7684\u672a\u6765\u8bbf\u95ee\u9875\u9762\u4e2d\uff0c\u5219\u5c06\u5b83\u6dfb\u52a0\u5230\u672a\u6765\u9875\u9762\u5b57\u5178\u4e2d\n        if pages&#91;i] not in future_pages:\n            future_pages&#91;pages&#91;i]] = i\n    return future_pages\n\n# OPT \u7b97\u6cd5\ndef optimal(page_reference_string, num_frames):\n    frames = &#91;]  # \u5b58\u50a8\u9875\u9762\u5e27\n    page_faults = 0  # \u7f3a\u9875\u6b21\u6570\n\n    print(\"\\nOPT\u7b97\u6cd5\\n\")\n\n    for i, page in enumerate(page_reference_string):\n        if page not in frames:\n            # \u5982\u679c\u9875\u9762\u4e0d\u5728\u5e27\u4e2d\uff0c\u8fdb\u884c\u9875\u9762\u7f6e\u6362\n            if len(frames) &lt; num_frames:\n                frames.append(page)  # \u5982\u679c\u5e27\u672a\u6ee1\uff0c\u76f4\u63a5\u52a0\u5165\u9875\u9762\u5e27\n            else:\n                # \u83b7\u53d6\u672a\u6765\u9875\u9762\u8bbf\u95ee\u4fe1\u606f\n                future_pages = get_future_pages(page_reference_string, i)\n                index_to_replace = -1\n                max_future_index = -1\n                # \u904d\u5386\u5f53\u524d\u9875\u9762\u5e27\u8fdb\u884c\u7f6e\u6362\u9009\u62e9\n                for frame_index, frame in enumerate(frames):\n                    # \u5982\u679c\u9875\u9762\u4e0d\u5728\u672a\u6765\u8bbf\u95ee\u5e8f\u5217\u4e2d\uff0c\u5219\u7f6e\u6362\u5f53\u524d\u9875\u9762\n                    if frame not in future_pages:\n                        index_to_replace = frame_index\n                        break\n                    # \u5982\u679c\u9875\u9762\u5728\u672a\u6765\u8bbf\u95ee\u5e8f\u5217\u4e2d\uff0c\u5e76\u4e14\u5176\u8bbf\u95ee\u4f4d\u7f6e\u66f4\u8fdc\uff0c\u5219\u9009\u62e9\u8be5\u9875\u9762\u8fdb\u884c\u7f6e\u6362\n                    elif future_pages&#91;frame] &gt; max_future_index:\n                        max_future_index = future_pages&#91;frame]\n                        index_to_replace = frame_index\n\n                frames&#91;index_to_replace] = page  # \u8fdb\u884c\u9875\u9762\u7f6e\u6362\n            page_faults += 1  # \u589e\u52a0\u7f3a\u9875\u6b21\u6570\u7edf\u8ba1\n\n        # \u6253\u5370\u6bcf\u6b21\u9875\u9762\u8bbf\u95ee\u540e\u7684\u9875\u9762\u5e27\u60c5\u51b5\n        print(\"\u5f53\u524d\u9875\u9762\u8bbf\u95ee\u5e8f\u5217: {}\uff0c\u7269\u7406\u5757\u88c5\u5165\u60c5\u51b5: {}\".format(page, frames))\n\n    return page_faults  # \u8fd4\u56de\u7f3a\u9875\u6b21\u6570\n\n# \u751f\u6210\u968f\u673a\u9875\u9762\u8bbf\u95ee\u5e8f\u5217\ndef generate_page_sequence(length):\n    return &#91;random.randint(0, 9) for _ in range(length)]\n\n# \u4e3b\u7a0b\u5e8f\ndef main():\n    num_frames = int(input(\"\u8bf7\u8f93\u5165\u5206\u914d\u7ed9\u8fdb\u7a0b\u7684\u7269\u7406\u5757\u6570\uff1a\"))\n\n    sequence_length = 20\n    page_sequence = generate_page_sequence(sequence_length)\n    print(\"\\n\u968f\u673a\u9875\u9762\u8bbf\u95ee\u5e8f\u5217\uff1a\", page_sequence)\n    \n    while True:\n        print('\u8bf7\u8f93\u5165\u9700\u8981\u9009\u62e9\u7684\u7b97\u6cd5\uff1a1\u3001FIFO   2\u3001LRU   3\u3001OPT   4\u3001\u9000\u51fa')\n        a = input()\n        if int(a)==1:\n            page_faults = fifo(page_sequence, num_frames)\n            page_fault_rate = page_faults \/ sequence_length * 100\n            print(\"\\n\u7f3a\u9875\u6b21\u6570\uff1a\", page_faults)\n            print(\"\u7f3a\u9875\u7387\uff1a{:.2f}%\".format(page_fault_rate))\n        elif int(a) == 2:\n            lru = LRU(num_frames)\n            print(\"\\nLRU\u9875\u9762\u7f6e\u6362\u7b97\u6cd5\\n\")\n            for page in page_sequence:\n                lru.reference_page(page)\n                lru.display_frames(page)\n\n            page_faults = lru.get_page_faults()\n            page_fault_rate = page_faults \/ sequence_length * 100\n            print(\"\\n\u7f3a\u9875\u6b21\u6570\uff1a\", page_faults)\n            print(\"\u7f3a\u9875\u7387\uff1a{:.2f}%\".format(page_fault_rate))\n        elif int(a)==3:\n            page_faults = optimal(page_sequence, num_frames)\n            page_fault_rate = page_faults \/ sequence_length * 100\n            print(\"\\n\u7f3a\u9875\u6b21\u6570\uff1a\", page_faults)\n            print(\"\u7f3a\u9875\u7387\uff1a{:.2f}%\".format(page_fault_rate))\n        else:\n            break\n\nif __name__ == \"__main__\":\n    main()<\/code><\/pre>\n\n\n\n<p><\/p>\n\n\n\n\n\n<p><\/p>\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e00\u3001\u5b9e\u73b0\u8981\u6c42 \uff081\uff09\u7cfb\u7edf\u91c7\u7528\u56fa\u5b9a\u5206\u914d\u3001\u5c40\u90e8\u7f6e\u6362\u7684\u7b56\u7565\uff082)  [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":211,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2],"tags":[],"class_list":["post-102","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-2"],"_links":{"self":[{"href":"https:\/\/blog.zwdblog.online\/index.php\/wp-json\/wp\/v2\/posts\/102","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.zwdblog.online\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.zwdblog.online\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.zwdblog.online\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.zwdblog.online\/index.php\/wp-json\/wp\/v2\/comments?post=102"}],"version-history":[{"count":0,"href":"https:\/\/blog.zwdblog.online\/index.php\/wp-json\/wp\/v2\/posts\/102\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blog.zwdblog.online\/index.php\/wp-json\/wp\/v2\/media\/211"}],"wp:attachment":[{"href":"https:\/\/blog.zwdblog.online\/index.php\/wp-json\/wp\/v2\/media?parent=102"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.zwdblog.online\/index.php\/wp-json\/wp\/v2\/categories?post=102"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.zwdblog.online\/index.php\/wp-json\/wp\/v2\/tags?post=102"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}