Re: C / 3 Dim. Array dynamisch allokieren (Bugfix)

4 Mar 2003


      On Tuesday 04 March 2003 10:33, Sebastian Huber wrote:
...
#include <iostream>
#include 
using namespace std;
void f( int a, int b, int c)
{
  int* a1 = (int*) malloc( a * b * c);
  int a2 [a][b][c];
  for (int i = 0; i < a; ++i) {
      for (int j = 0; j < b; ++j) {
      	for (int k = 0; k < c; ++k) {
      		cout << (*(a1 + i * a * b + j * b + k) = i * 100 + j * 10 + k) << " ==
" << (a2 [i][j][k] = i * 100 + j * 10 + k) << "\t";
      	}
      	cout << endl;
      }
      cout << endl;
  }
}
Das ist natuerlich Unfug, da etwas wenig Speicher anlegt wird, so muesste es 
passen:

void f( int a, int b, int c)
{
	int* a1 = (int*) malloc( a * b * c * sizeof( int));
	int a2 [a][b][c];
	for (int i = 0; i < a; ++i) {
		for (int j = 0; j < b; ++j) {
			for (int k = 0; k < c; ++k) {
				cout << (*(a1 + i * a * b + j * b + k) = i * 100 + j * 10 + k)
					<< " == " << (a2 [i][j][k] = i * 100 + j * 10 + k) << "\t";
			}
			cout << endl;
		}
		cout << endl;
	}
}