新矩阵[N] [N]失败 [英] new matrix[N][N] failure

问题描述

我有一个堆栈溢出在堆栈上分配一个巨大的矩阵（我同意：它很愚蠢的分配它），我写下面的代码，因为我想访问矩阵的元素与下标indices mat [x] [y]

  double（* mul1）[N] [N] 
 mul1 = new double [N] [N]; 
  

我收到一个错误：

 错误C2440：'='：无法从'double（*）[1000]'转换为double（*）[1000] [1000]'
  
 
 
 
为什么我不能用新的分配一个二维数组？
解决方案
 
  double * mul1 [N]; 
 for（int i = 0; i  mul1 [i] = new double [N]; 
  
 将2D数组表示为1D数组 
 
 
 
  2维数组与1维数组的性能 
 
I'm having a stack overflow allocating a huge matrix on the stack (and I agree with that: it's stupid to allocate it there) and I'm writing the following code since I want to access the matrix's elements with the subscripts indices mat[x][y]
double (*mul1)[N][N];
mul1 = new double[N][N];
I'm receiving an error: 
error C2440: '=' : cannot convert from 'double (*)[1000]' to 'double(*)[1000][1000]'
Why can't I allocate a bidimensional array with new?
解决方案
double *mul1[N];
for (int i=0;i<N;++i)
    mul1[i] = new double[N];
Representing a 2D array as a 1D array

Performance of 2-dimensional array vs 1-dimensional array

                        
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