c++ - C/C++ 运行时多维动态数组

Question

我有以下结构:

typedef struct _DynamicArray {
    int *data = nullptr;
    _DynamicArray *ptr_next = nullptr;
    _DynamicArray *ptr_dim = nullptr;
} DynamicArray; // so that every matrix cell contains another matrix cell

然后是下面的递归方法:

void _BuildArray(std::string const& source, StringIterator& sit, DynamicArray *dArray, bool& error) {
    if (!error) {
        while (sit+1 < source.length()) {
            ++sit;
            switch (source[sit]) {
                case '[':
                    dArray->ptr_dim = new DynamicArray();
                    _BuildArray(source, sit, dArray->ptr_dim, error);
                    break;
                case ']':
                    return;
                case ',':
                    break;
                case ' ':
                    break;
                default:
                    std::string str;
                    while (std::isdigit(source[sit])) {
                        str.push_back(source[sit]);
                        ++sit;
                    }
                    --sit;
                    if (str.empty()) {
                        error = true;
                        return;
                    }
                    else {
                        dArray->data = new int(stoi(str));
                        dArray->ptr_next = new DynamicArray();
                        dArray = dArray->ptr_next;
                    }
                    break;
            }
        }
    }
}

然后如果我将“[[1], 2, [[3,4], 5], [[[]]], [[[6]]], 7, 8, []]”作为一个参数，它构建以下展平:“[1,2,6,7,8]”(而不是“[1,2,3,4,5,6,7,8]”)。为什么？

调用片段是这样的:

StringIterator sit = 0;
bool error = false;
this->dynArray = new DynamicArray();
_BuildArray(this->listString, sit, this->dynArray, error);

Answer 1

一旦您的递归 _BuildArray 调用返回，您就不会像在 default: 情况下那样推进 dArray。这意味着您遇到的下一个 [ 将覆盖前一个 [ 的结果。