初始化后可以调整 C++ 数组的大小吗? [英] Can you resize a C++ array after initialization?

问题描述

我正在学习编程，C++ 是我的第一门语言.不要费心使用指针来向我展示 - 我还不理解它们，并且在我有更多空闲时间致力于此之前不会打扰.

I'm learning to program, and C++ is my first language. Don't bother using pointers to show me - I don't understand them yet, and won't bother until I have more free time to dedicate to this.

    int mergeSort()
{
    const int n = 9;
    int originalarray[n] = {1, 3, 5, 7, 9, 2, 4, 6, 8};


    const int halfelements = (sizeof(originalarray) / sizeof(int)) / 2;
    int farray[halfelements];
    int sarray[halfelements];

    for (int i = 0; i < halfelements; i++) {
        farray[i] = originalarray[i];
    }

    for (int i = halfelements, x = 0; i < (halfelements * 2); i++, x++) {
        sarray[x] = originalarray[i];
    }

我被分配了(我没有上课 - 只是和几个帮助我的朋友一起学习)一个合并排序算法，其中解释了算法，但没有解释实现.我想重写它，以便它适用于奇数和偶数整数.我尝试添加此代码:

I was assigned (I'm not taking classes - just learning with a few friends helping me out) a merge sort algorithm, with the algorithm explained but not the implementation. I want to rewrite this so it will work for both odd and even integers. I tried adding this code:

if ((n % 2) != 0) int farray[halfelements + 1];

这样我就可以使用相同的整数来迭代两个后续数组.sizeof(farray) 显示为 16 个字节，或 4 个整数.所以它没有调整大小.我想知道 - 是否可以在初始化后调整数组大小?

So that I could use the same integer to iterate over both subsequent arrays. A sizeof(farray) is showing to be 16 bytes, or 4 integers. So it isn't resizing. What I want to know - is it possible to resize arrays after they initialized?

我将如何实现向量?我不明白如何在循环中使用迭代器来迭代和复制值.

How would I implement a vector? I don't understand how to use iterators in a loop to iterate over and copy the values.

推荐答案

C++ 数组的大小是固定的.

C++ arrays are fixed in size.

如果你需要一个可调整大小的数组"，你需要使用 std::vector 而不是数组.

If you need a "resizable array", you'll want to use std::vector instead of an array.

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