• <ins id="pjuwb"></ins>
    <blockquote id="pjuwb"><pre id="pjuwb"></pre></blockquote>
    <noscript id="pjuwb"></noscript>
          <sup id="pjuwb"><pre id="pjuwb"></pre></sup>
            <dd id="pjuwb"></dd>
            <abbr id="pjuwb"></abbr>

            C++研究

            C++細節深度探索及軟件工程

              C++博客 :: 首頁 :: 新隨筆 :: 聯系 :: 聚合  :: 管理 ::
              37 隨筆 :: 0 文章 :: 74 評論 :: 0 Trackbacks
            By default, you should use a vector. It has the simplest internal data structure and
            provides random access. Thus, data access is convenient and flexible, and data
            processing is often fast enough.

            • If you insert and/or remove elements often at the beginning and the end of a sequence,
            you should use a deque. You should also use a deque if it is important that the amount of
            internal memory used by the container shrinks when elements are removed. Also,
            because a vector usually uses one block of memory for its elements, a deque might be
            able to contain more elements because it uses several blocks.

            • If you insert, remove, and move elements often in the middle of a container, consider
            using a list. Lists provide special member functions to move elements from one container
            to another in constant time. Note, however, that because a list provides no random access, you might suffer significant performance penalties on access to elements inside
            the list if you only have the beginning of the list.
            Like all node-based containers, a list doesn't invalidate iterators that refer to elements, as
            long as those elements are part of the container. Vectors invalidate all of their iterators,
            pointers, and references whenever they exceed their capacity, and part of their iterators,
            pointers, and references on insertions and deletions. Deques invalidate iterators,
            pointers, and references when they change their size, respectively.

            • If you need a container that handles exceptions in a way that each operation either
            succeeds or has no effect, you should use either a list (without calling assignment
            operations and sort() and, if comparing the elements may throw, without calling merge
            (), remove(), remove_if(), and unique(); see page 172) or an associative
            container (without calling the multiple-element insert operations and, if copying/assigning
            the comparison criterion may throw, without calling swap()). See Section 5.11.2, for a
            general discussion of exception handling in the STL and Section 6.10.10, for a table of
            all container operations with special guarantees in face of exceptions.

            • If you often need to search for elements according to a certain criterion, use a set or a
            multiset that sorts elements according to this sorting criterion. Keep in mind that the
            logarithmic complexity involved in sorting 1,000 elements is in principle ten times better
            than that with linear complexity. In this case, the typical advantages of binary trees apply.
            A hash table commonly provides five to ten times faster lookup than a binary tree. So if a
            hash container is available, you might consider using it even though hash tables are not
            standardized. However, hash containers have no ordering, so if you need to rely on
            element order they're no good. Because they are not part of the C++ standard library, you
            should have the source code to stay portable.

            Quoted from STL_tutorial_reference
            posted on 2007-04-21 14:39 常興龍 閱讀(287) 評論(0)  編輯 收藏 引用
            > hi的博客
            人妻无码精品久久亚瑟影视| 色欲av伊人久久大香线蕉影院 | 99热都是精品久久久久久| 久久午夜伦鲁片免费无码| 久久综合综合久久狠狠狠97色88| 看全色黄大色大片免费久久久| 国内精品久久久久久久久电影网 | 国产精品久久午夜夜伦鲁鲁| 丁香五月综合久久激情| 77777亚洲午夜久久多喷| 狠狠人妻久久久久久综合| 亚洲AV乱码久久精品蜜桃| 久久午夜无码鲁丝片午夜精品| 久久婷婷国产综合精品| 欧美日韩成人精品久久久免费看| 久久永久免费人妻精品下载| 久久久久亚洲AV无码专区桃色 | 色天使久久综合网天天| 久久精品国产影库免费看| 国产成人精品久久| 精品人妻伦九区久久AAA片69| 久久精品欧美日韩精品| 久久狠狠爱亚洲综合影院| 久久久久免费视频| 91精品国产综合久久香蕉 | 久久亚洲AV无码西西人体| 久久久久99精品成人片试看 | 国产激情久久久久久熟女老人| 久久精品三级视频| 国产成人精品久久亚洲高清不卡 国产成人精品久久亚洲高清不卡 国产成人精品久久亚洲 | 久久久久亚洲精品无码网址 | 亚洲日本va中文字幕久久| 亚洲v国产v天堂a无码久久| 国产成人久久777777| 亚洲欧美精品伊人久久| 国产一级持黄大片99久久| 久久夜色精品国产噜噜噜亚洲AV | 久久无码一区二区三区少妇 | 久久精品中文字幕一区| 精品国产青草久久久久福利| 热99RE久久精品这里都是精品免费 |