• <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
            欧洲人妻丰满av无码久久不卡| 精品国产乱码久久久久久1区2区| 99久久精品国产综合一区| 国产综合久久久久| 国产视频久久| 午夜精品久久久久| 久久国产精品77777| 7国产欧美日韩综合天堂中文久久久久 | 一本色道久久88综合日韩精品 | 久久99国产精品久久99果冻传媒| 精品久久久久久无码中文野结衣 | 久久久噜噜噜久久中文福利| 国产精品无码久久综合网| 伊人久久综合成人网| 91麻精品国产91久久久久| 新狼窝色AV性久久久久久| 久久人人爽人爽人人爽av| 国产69精品久久久久777| 亚洲欧洲日产国码无码久久99| 国产呻吟久久久久久久92| 久久不见久久见免费视频7| 久久影视综合亚洲| 国产免费福利体检区久久| 国产精品久久99| 人妻久久久一区二区三区| 久久久久久伊人高潮影院| 欧美伊人久久大香线蕉综合69| 欧美一区二区精品久久| 77777亚洲午夜久久多喷| 九九久久自然熟的香蕉图片| 亚洲欧美成人综合久久久| 亚洲色欲久久久久综合网| 久久久中文字幕日本| 久久综合九色综合久99| 久久亚洲电影| 亚洲国产成人精品无码久久久久久综合| 91精品国产综合久久精品| 伊人久久大香线蕉AV色婷婷色| 国产99久久久国产精品小说 | 久久精品视频网| 久久精品国产亚洲麻豆|