动态地分配向量（或向量的向量） [英] allocating vectors (or vectors of vectors) dynamically

问题描述

我需要动态分配大小在运行时给定的1-D和2-D数组。

I need to dynamically allocate 1-D and 2-D arrays whose sizes are given at run-time.

我设法发现 std :: vector 我认为这符合我的目的，但我想问，我写的是否正确和/或可以改进。

I managed to "discover" std::vector and I think it fits my purposes, but I would like to ask whether what I've written is correct and/or can be improved.

这是我在做什么：

#include <vector>

typedef std::vector< std::vector<double> > matrix;

//... various code and other stuff

std::vector<double> *name = new std::vector<double> (size);
matrix *name2 = new matrix(sizeX, std::vector<double>(sizeY));

推荐答案

但是， std :: vector 已经是一个围绕这个过程，所以动态分配向量就像一个双正。这是多余的。

However, std::vector is already a wrapper around this process, so dynamically allocating vectors is like a double positive. It's redundant.

只要写：

#include <vector>

typedef std::vector< std::vector<double> > matrix;
matrix name(sizeX, std::vector<double>(sizeY));

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