{"id":147,"date":"2021-10-13T18:38:09","date_gmt":"2021-10-13T10:38:09","guid":{"rendered":"http:\/\/139.224.63.49\/?p=147"},"modified":"2021-10-13T18:38:09","modified_gmt":"2021-10-13T10:38:09","slug":"%e5%af%b9%e4%ba%8estl-vector%e7%9a%84%e4%b8%80%e4%ba%9b%e5%b0%8f%e7%bb%86%e8%8a%82","status":"publish","type":"post","link":"http:\/\/iamnear.top\/?p=147","title":{"rendered":"\u5bf9\u4e8estl vector\u7684\u4e00\u4e9b\u5c0f\u7ec6\u8282"},"content":{"rendered":"\n<p>\u4ee5\u4e0b\u7ed3\u8bba\u90fd\u662f\u57fa\u4e8eDebian 4.19.132-1 (2020-07-24) x86_64 GNU\/Linux\uff0cg++ (Debian 8.3.0-6) 8.3.0\u5f97\u51fa<\/p>\n\n\n\n<p>1\u3001\u8981\u4f7f\u7528vector\u6765\u505a\u4e8c\u7ef4\u6570\u7ec4\u7684\u65f6\u5019\uff0c\u7ecf\u5e38\u4f1a\u8fd9\u4e48\u5199\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>vector&lt;vector&lt;int>> dp(3,vector&lt;int>(4));<\/code><\/pre>\n\n\n\n<p>\u90a3\u4e48\u95ee\u9898\u6765\u4e86\uff0c\u8fd9\u53e5\u8bdd\u4e00\u5171\u8c03\u7528\u4e86\u51e0\u6b21\u6784\u9020\u51fd\u6570\uff0c\u7533\u8bf7\u4e86\u51e0\u6b21\u5185\u5b58\uff1f<\/p>\n\n\n\n<p>\u8c03\u7528\u4e865\u6b21\u6784\u9020\u51fd\u6570<\/p>\n\n\n\n<p>\u7b2c\u4e00\u6b21\u662f\u8c03\u7528\u4e34\u65f6\u53d8\u91cf vector&lt;int>(4) \u7684\u6784\u9020\u51fd\u6570\uff0c\u7533\u8bf7\u4e86sizeof(int)*4\u7684\u5185\u5b58<\/p>\n\n\n\n<p>\u7b2c\u4e8c\u6b21\u662f\u8c03\u7528dp\u7684\u6784\u9020\u51fd\u6570\uff0c\u7533\u8bf7\u4e86sizeof(vector&lt;int>)*3\u7684\u5185\u5b58<\/p>\n\n\n\n<p>\u7b2c\u4e09\u6b21\u5230\u7b2c\u4e94\u6b21\u90fd\u662f\u8c03\u7528dp[0],dp[1],dp[2]\u7684\u62f7\u8d1d\u6784\u9020\u51fd\u6570\uff0c\u5206\u522b\u7533\u8bf7\u4e86sizeof(int)*4\u7684\u5185\u5b58<\/p>\n\n\n\n<p>2\u3001vector\u5185\u5b58\u589e\u957f\u7684\u89c4\u5f8b\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>      _M_check_len(size_type __n, const char* __s) const\n      {\n\tif (max_size() - size() &lt; __n)\n\t  __throw_length_error(__N(__s));\n\n\tconst size_type __len = size() + std::max(size(), __n);\n\treturn (__len &lt; size() || __len > max_size()) ? max_size() : __len;\n      }<\/code><\/pre>\n\n\n\n<p>\u56e0\u6b64\u57fa\u672c\u4e0a\u5c31\u662fnewsize = size + max(size,n),n\u5c31\u662f\u4f60\u65b0\u63d2\u5165\u7684\u957f\u5ea6\u3002\u5f53\u6bcf\u6b21\u53ea\u63d2\u5165\u4e00\u4e2a\u5143\u7d20\u7684\u65f6\u5019\uff0c\u90a3\u4e48vector\u7684capacity\u5c31\u4f1a\u4ee52\u7684\u6307\u6570\u589e\u957f\u3002<\/p>\n\n\n\n<p>3\u3001vector\u5728\u6269\u5bb9\u7684\u65f6\u5019\uff0c\u662f\u7528malloc\u8fd8\u662frealloc\uff1f<\/p>\n\n\n\n<p>\u6839\u636e\u6211\u7684\u5e73\u53f0\u73af\u5883\u6765\u770b\uff0c\u662f\u7528malloc\u7533\u8bf7\u4e2a\u66f4\u5927\u7684\u5730\u5740<\/p>\n\n\n\n<p>4\u3001vector\u6269\u5bb9\u4ee5\u540e\uff0c\u600e\u6837\u91cd\u65b0\u6784\u9020\u5bf9\u8c61\uff1f<\/p>\n\n\n\n<p>\u5982\u679c\u6709noexcept \u7684\u79fb\u52a8\u6784\u9020\u51fd\u6570\uff0c\u90a3\u5c31\u7528\u79fb\u52a8\u6784\u9020\uff0c\u6ca1\u6709\u7684\u8bdd\uff0c\u5c31\u7528\u62f7\u8d1d\u6784\u9020\u51fd\u6570\u3002\u6240\u4ee5\u4f60\u5149\u5199\u4e86\u79fb\u52a8\u6784\u9020\u51fd\u6570\u8fd8\u4e0d\u884c\uff0c\u4e00\u5b9a\u8981noexcept\uff01\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4ee5\u4e0b\u7ed3\u8bba\u90fd\u662f\u57fa\u4e8eDebian 4.19.132-1 (2020-07-24) x86_64 GNU\/&hellip; <a href=\"http:\/\/iamnear.top\/?p=147\" class=\"more-link read-more\" rel=\"bookmark\">\u7ee7\u7eed\u9605\u8bfb <span class=\"screen-reader-text\">\u5bf9\u4e8estl vector\u7684\u4e00\u4e9b\u5c0f\u7ec6\u8282<\/span><i class=\"fa fa-arrow-right\"><\/i><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4,1],"tags":[],"class_list":{"0":"post-147","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"hentry","6":"category-c_plus_plus","7":"category-uncategorized","8":"h-entry","10":"h-as-article"},"_links":{"self":[{"href":"http:\/\/iamnear.top\/index.php?rest_route=\/wp\/v2\/posts\/147","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/iamnear.top\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/iamnear.top\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/iamnear.top\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/iamnear.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=147"}],"version-history":[{"count":1,"href":"http:\/\/iamnear.top\/index.php?rest_route=\/wp\/v2\/posts\/147\/revisions"}],"predecessor-version":[{"id":148,"href":"http:\/\/iamnear.top\/index.php?rest_route=\/wp\/v2\/posts\/147\/revisions\/148"}],"wp:attachment":[{"href":"http:\/\/iamnear.top\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=147"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/iamnear.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=147"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/iamnear.top\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=147"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}