{"id":384,"date":"2025-07-20T00:04:16","date_gmt":"2025-07-19T16:04:16","guid":{"rendered":"https:\/\/www.hgfwq.com\/blog\/?p=384"},"modified":"2025-07-20T00:04:16","modified_gmt":"2025-07-19T16:04:16","slug":"c-log2%e5%b8%a6%e4%bd%a0%e6%b7%b1%e5%85%a5%e5%af%b9%e6%95%b0%e7%9a%84%e9%ad%85%e5%8a%9b%e4%b8%96%e7%95%8c%ef%bc%81","status":"publish","type":"post","link":"https:\/\/www.hgfwq.com\/blog\/384.html","title":{"rendered":"C++ log2\u5e26\u4f60\u6df1\u5165\u5bf9\u6570\u7684\u9b45\u529b\u4e16\u754c\uff01"},"content":{"rendered":"<p><h>\u4ec0\u4e48\u662fC++\u4e2d\u7684log2\u51fd\u6570\uff1f<\/h><\/p>\n<p style=\"text-align:center\"><img decoding=\"async\" src=\"https:\/\/www.hgfwq.com\/blog\/wp-content\/uploads\/2025\/07\/2I6E1RhZwe.jpg\" alt=\"C++ log2\u5e26\u4f60\u6df1\u5165\u5bf9\u6570\u7684\u9b45\u529b\u4e16\u754c\uff01\" title=\"C++ log2\u5e26\u4f60\u6df1\u5165\u5bf9\u6570\u7684\u9b45\u529b\u4e16\u754c\uff01\"><\/p>\n<p><p>C++\u4e2d\u7684log2\u51fd\u6570\u662f\u6807\u51c6\u5e93\u4e2d\u7684cmath\u5934\u6587\u4ef6\u63d0\u4f9b\u7684\u4e00\u4e2a\u6570\u5b66\u51fd\u6570\uff0c\u7528\u4e8e\u8ba1\u7b97\u4ee52\u4e3a\u5e95\u7684\u5bf9\u6570\u3002\u8fd9\u4e2a\u51fd\u6570\u53ef\u4ee5\u7528\u6765\u5c06\u4e00\u4e2a\u6570\u5b57\u8f6c\u6362\u4e3a\u51762\u7684\u5e42\u6b21\u5f62\u5f0f\uff0c\u8fd9\u5728\u5904\u7406\u4e8c\u8fdb\u5236\u6570\u636e\u3001\u4f4d\u64cd\u4f5c\u6216\u8005\u8ba1\u7b97\u4e8c\u8fdb\u5236\u6570\u4e2d\u7684\u4f4d\u6570\u65f6\u975e\u5e38\u6709\u7528\u3002<\/p>\n<\/p>\n<p><h>\u5982\u4f55\u5728C++\u4e2d\u4f7f\u7528log2\u51fd\u6570\uff1f<\/h><\/p>\n<p><p>\u8981\u5728C++\u4e2d\u4f7f\u7528log2\u51fd\u6570\uff0c\u9996\u5148\u9700\u8981\u5305\u542bcmath\u5934\u6587\u4ef6\u3002\u4ee5\u4e0b\u662f\u4f7f\u7528log2\u51fd\u6570\u7684\u57fa\u672c\u6b65\u9aa4\uff1a<\/p>\n<\/p>\n<ol>\n<li>\n<p><p>\u5305\u542bcmath\u5934\u6587\u4ef6\uff1a<\/p>\n<\/p>\n<p>  &#8220;`cpp<\/p>\n<p>  include <cmath><\/p>\n<p>  &#8220;`<\/p>\n<\/li>\n<li>\n<p><p>\u4f7f\u7528log2\u51fd\u6570\u8ba1\u7b97\u5bf9\u6570\uff1a<\/p>\n<\/p>\n<p>  &#8220;`cpp<\/p>\n<p>  double result = log2(8); \/\/ \u8ba1\u7b97\u4ee52\u4e3a\u5e958\u7684\u5bf9\u6570<\/p>\n<p>  &#8220;`<\/p>\n<\/li>\n<li>\n<p><p>\u5904\u7406\u53ef\u80fd\u7684\u9519\u8bef\u60c5\u51b5\uff1a<\/p>\n<\/p>\n<p>  &#8220;`cpp<\/p>\n<p>  if(result != -INFINITY) {<\/p>\n<p>      \/\/ \u5bf9\u6570\u8ba1\u7b97\u6210\u529f\uff0cresult\u5305\u542b\u4e86\u7ed3\u679c<\/p>\n<p>  } else {<\/p>\n<p>      \/\/ \u5bf9\u6570\u8ba1\u7b97\u5931\u8d25\uff0c\u53ef\u80fd\u662f\u53c2\u6570\u5c0f\u4e8e\u7b49\u4e8e0<\/p>\n<p>  }<\/p>\n<p>  &#8220;`<\/p>\n<\/li>\n<\/ol>\n<p><h>log2\u51fd\u6570\u7684\u53c2\u6570\u548c\u8fd4\u56de\u503c<\/h><\/p>\n<p><p>log2\u51fd\u6570\u63a5\u53d7\u4e00\u4e2a\u53c2\u6570\uff0c\u5373\u8981\u8ba1\u7b97\u5bf9\u6570\u7684\u6570\u503c\u3002\u8fd9\u4e2a\u6570\u503c\u53ef\u4ee5\u662f\u4efb\u4f55\u6b63\u6570\uff0c\u5305\u62ec\u6d6e\u70b9\u6570\u3002log2\u51fd\u6570\u7684\u8fd4\u56de\u503c\u662f\u5bf9\u6570\u7684\u7ed3\u679c\uff0c\u5982\u679c\u53c2\u6570\u5c0f\u4e8e\u7b49\u4e8e0\uff0c\u5219\u8fd4\u56de-Infinity\uff0c\u8868\u793a\u9519\u8bef\u3002<\/p>\n<\/p>\n<p><p>\u4ee5\u4e0b\u662flog2\u51fd\u6570\u7684\u53c2\u6570\u548c\u8fd4\u56de\u503c\u793a\u4f8b\uff1a<\/p>\n<\/p>\n<ul>\n<li>\n<p><p>\u53c2\u6570\uff1a\u6b63\u6570<\/p>\n<\/p>\n<p>  &#8220;`cpp<\/p>\n<p>  double result = log2(16); \/\/ \u8fd4\u56de\u503c\u4e3a4<\/p>\n<p>  &#8220;`<\/p>\n<\/li>\n<li>\n<p><p>\u53c2\u6570\uff1a1<\/p>\n<\/p>\n<p>  &#8220;`cpp<\/p>\n<p>  double result = log2(1); \/\/ \u8fd4\u56de\u503c\u4e3a0<\/p>\n<p>  &#8220;`<\/p>\n<\/li>\n<li>\n<p><p>\u53c2\u6570\uff1a0<\/p>\n<\/p>\n<p>  &#8220;`cpp<\/p>\n<p>  double result = log2(0); \/\/ \u8fd4\u56de\u503c\u4e3a-Infinity<\/p>\n<p>  &#8220;`<\/p>\n<\/li>\n<li>\n<p><p>\u53c2\u6570\uff1a\u8d1f\u6570<\/p>\n<\/p>\n<p>  &#8220;`cpp<\/p>\n<p>  double result = log2(-8); \/\/ \u8fd4\u56de\u503c\u4e3a-Infinity<\/p>\n<p>  &#8220;`<\/p>\n<\/li>\n<\/ul>\n<p><h>log2\u51fd\u6570\u5728\u670d\u52a1\u5668\/vps\/\u4e3b\u673a\/\u57df\u540d\/\u6280\u672f\u4e2d\u7684\u5e94\u7528<\/h><\/p>\n<p><p>log2\u51fd\u6570\u5728\u670d\u52a1\u5668\u3001\u865a\u62df\u79c1\u4eba\u670d\u52a1\u5668\uff08VPS\uff09\u3001\u4e3b\u673a\u548c\u57df\u540d\u6280\u672f\u4e2d\u6709\u7740\u5e7f\u6cdb\u7684\u5e94\u7528\uff0c\u4ee5\u4e0b\u662f\u4e00\u4e9b\u5177\u4f53\u7684\u5e94\u7528\u573a\u666f\uff1a<\/p>\n<\/p>\n<ol>\n<li>\n<p><p>\u8ba1\u7b97\u5185\u5b58\u6216\u5b58\u50a8\u5bb9\u91cf<\/p>\n<\/p>\n<p><p>\u5728\u670d\u52a1\u5668\u914d\u7f6e\u4e2d\uff0clog2\u51fd\u6570\u53ef\u4ee5\u7528\u6765\u8ba1\u7b97\u5185\u5b58\u6216\u5b58\u50a8\u5bb9\u91cf\u7684\u5927\u5c0f\u3002\u4f8b\u5982\uff0c\u5982\u679c\u670d\u52a1\u5668\u67098GB\u7684RAM\uff0c\u53ef\u4ee5\u4f7f\u7528log2(8)\u6765\u8ba1\u7b97\u5b83\u5305\u542b\u76842\u7684\u5e42\u6b21\u6570\uff0c\u53732^3\uff0c\u4ece\u800c\u786e\u5b9a\u5176\u5927\u5c0f\u4e3a2\u76843\u6b21\u5e42\u3002<\/p>\n<\/li>\n<li>\n<p><p>\u4f18\u5316\u4f4d\u64cd\u4f5c<\/p>\n<\/p>\n<p><p>\u5728\u7f16\u7a0b\u4e2d\uff0c\u4f4d\u64cd\u4f5c\u662f\u63d0\u9ad8\u6027\u80fd\u7684\u5173\u952e\u3002log2\u51fd\u6570\u53ef\u4ee5\u5e2e\u52a9\u786e\u5b9a\u4e00\u4e2a\u6570\u5b57\u5728\u4e8c\u8fdb\u5236\u8868\u793a\u4e2d\u7684\u4f4d\u6570\uff0c\u4ece\u800c\u4f18\u5316\u4f4d\u64cd\u4f5c\u7b97\u6cd5\u3002<\/p>\n<\/li>\n<li>\n<p><p>\u5904\u7406\u4e8c\u8fdb\u5236\u6570\u636e<\/p>\n<\/p>\n<p><p>\u5728\u5904\u7406\u4e8c\u8fdb\u5236\u6570\u636e\u65f6\uff0clog2\u51fd\u6570\u53ef\u4ee5\u7528\u6765\u8ba1\u7b97\u6570\u636e\u7684\u4f4d\u6570\uff0c\u8fd9\u5bf9\u4e8e\u538b\u7f29\u548c\u89e3\u538b\u7f29\u4e8c\u8fdb\u5236\u6570\u636e\u975e\u5e38\u91cd\u8981\u3002<\/p>\n<\/li>\n<\/ol>\n<p><h>\u95ee\u7b54\u73af\u8282<\/h><\/p>\n<p><b>\u95ee\uff1alog2\u51fd\u6570\u5728\u670d\u52a1\u5668\u914d\u7f6e\u4e2d\u6709\u4ec0\u4e48\u4f5c\u7528\uff1f<\/b><\/p>\n<p><p>\u7b54\uff1alog2\u51fd\u6570\u5728\u670d\u52a1\u5668\u914d\u7f6e\u4e2d\u53ef\u4ee5\u7528\u6765\u8ba1\u7b97\u5185\u5b58\u6216\u5b58\u50a8\u5bb9\u91cf\u7684\u5927\u5c0f\uff0c\u5e2e\u52a9\u786e\u5b9a\u5176\u5305\u542b\u76842\u7684\u5e42\u6b21\u6570\uff0c\u4ece\u800c\u4f18\u5316\u8d44\u6e90\u914d\u7f6e\u3002<\/p>\n<\/p>\n<p><b>\u95ee\uff1alog2\u51fd\u6570\u5728\u4f4d\u64cd\u4f5c\u4e2d\u6709\u4ec0\u4e48\u5e94\u7528\uff1f<\/b><\/p>\n<p><p>\u7b54\uff1alog2\u51fd\u6570\u53ef\u4ee5\u7528\u6765\u786e\u5b9a\u4e00\u4e2a\u6570\u5b57\u5728\u4e8c\u8fdb\u5236\u8868\u793a\u4e2d\u7684\u4f4d\u6570\uff0c\u8fd9\u5bf9\u4e8e\u4f18\u5316\u4f4d\u64cd\u4f5c\u7b97\u6cd5\u548c\u63d0\u9ad8\u7a0b\u5e8f\u6027\u80fd\u975e\u5e38\u6709\u7528\u3002<\/p>\n<\/p>\n<p><b>\u95ee\uff1a\u4e3a\u4ec0\u4e48log2(0)\u4f1a\u8fd4\u56de-Infinity\uff1f<\/b><\/p>\n<p><p>\u7b54\uff1a\u56e0\u4e3a\u5bf9\u6570\u51fd\u6570\u7684\u5b9a\u4e49\u57df\u662f\u6b63\u5b9e\u6570\uff0c\u5bf9\u4e8e0\u6765\u8bf4\uff0c\u6ca1\u6709\u5e95\u6570\u4e3a2\u7684\u5bf9\u6570\uff0c\u6240\u4ee5log2(0)\u8fd4\u56de-Infinity\u4f5c\u4e3a\u9519\u8bef\u6307\u793a\u3002<\/p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4ec0\u4e48\u662fC++\u4e2d\u7684log2\u51fd\u6570\uff1f C++\u4e2d\u7684log2\u51fd\u6570\u662f\u6807\u51c6\u5e93\u4e2d\u7684cmath\u5934\u6587\u4ef6\u63d0\u4f9b\u7684\u4e00\u4e2a\u6570\u5b66\u51fd\u6570\uff0c\u7528\u4e8e\u8ba1\u7b97\u4ee52\u4e3a\u5e95\u7684\u5bf9\u6570\u3002\u8fd9\u4e2a\u51fd\u6570\u53ef\u4ee5\u7528\u6765\u5c06\u4e00\u4e2a\u6570\u5b57\u8f6c\u6362\u4e3a\u51762\u7684\u5e42\u6b21\u5f62\u5f0f\uff0c\u8fd9\u5728\u5904\u7406\u4e8c\u8fdb\u5236\u6570\u636e\u3001\u4f4d\u64cd\u4f5c\u6216\u8005\u8ba1\u7b97\u4e8c\u8fdb\u5236\u6570\u4e2d\u7684\u4f4d\u6570\u65f6\u975e\u5e38\u6709\u7528\u3002 \u5982&#8230;<\/p>\n","protected":false},"author":1,"featured_media":385,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[195,194,70],"topic":[],"class_list":["post-384","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-haiwai","tag-c","tag-log","tag-70"],"_links":{"self":[{"href":"https:\/\/www.hgfwq.com\/blog\/wp-json\/wp\/v2\/posts\/384","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.hgfwq.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.hgfwq.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.hgfwq.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.hgfwq.com\/blog\/wp-json\/wp\/v2\/comments?post=384"}],"version-history":[{"count":1,"href":"https:\/\/www.hgfwq.com\/blog\/wp-json\/wp\/v2\/posts\/384\/revisions"}],"predecessor-version":[{"id":387,"href":"https:\/\/www.hgfwq.com\/blog\/wp-json\/wp\/v2\/posts\/384\/revisions\/387"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.hgfwq.com\/blog\/wp-json\/wp\/v2\/media\/385"}],"wp:attachment":[{"href":"https:\/\/www.hgfwq.com\/blog\/wp-json\/wp\/v2\/media?parent=384"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.hgfwq.com\/blog\/wp-json\/wp\/v2\/categories?post=384"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.hgfwq.com\/blog\/wp-json\/wp\/v2\/tags?post=384"},{"taxonomy":"topic","embeddable":true,"href":"https:\/\/www.hgfwq.com\/blog\/wp-json\/wp\/v2\/topic?post=384"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}