C++动态二维数组示范

C++动态二维数组演示

#include <iostream>
#include <string>
using namespace std;
void allocate_2D(int **&List, int x, int y, int ycur, int xmax)
{
	//makes a temp for saving data that was in the array
	int **TEMP = List; 
	//creates a new array to the right size
	List = new int*[x];
	for( int i = 0; i < x; i++ )
	{
		List[i] = new int[y];
		for( int j = 0; j < y; j++ )
		{
			List[i][j] = 0;
		}
	}
	//copies info into newly allocated array
	for( int i = 0; i < xmax; i++ )
	{
		for( int j = 0; j <= ycur; j++ )	
		{
			List[i][j] = TEMP[i][j]; 
		}
	}
	//deletes the TEMP array
	for( int i = 0; i < ycur; i++ )
	{
		delete[] TEMP[i];
		TEMP[i] = 0;
	}
	delete[] TEMP;
	TEMP = 0;
}
int main()
{
	string input;
	int xsize = 1, ysize = 1;
	int xcur = 0, ycur = 0, xmax = 0;
	int **List;
	cout << "Enter some integers (input 'r' for new row and 's' for stop):" << endl;
	while(cin >> input)
	{
		if( input == "s" ) //done entering values
			break;
		else if( input == "r" ) //add a row
		{
			ysize++;
			allocate_2D(List, xsize, ysize, ycur, xmax); //makes a new array with another row
			xcur = 0;
			ycur += 1;
		}
		else
		{
			//add a value
			xsize++;
			allocate_2D(List, xsize, ysize, ycur, xmax); //makes a new array with another column
			List[xcur][ycur] = atoi(input.c_str()); //converts input to integer and adds it to the list
			xcur++;
			if( xcur > xmax ) //keeps track of the maxium width of the array
				xmax = xcur;
		}
	}
	//outputs the array
	for( int j = 0; j <= ycur; j++ )
	{
		for( int i = 0; i < xmax; i++ )
		{
			cout << List[i][j] << " ";
		}
		cout << endl;
	}
	system("PAUSE");
	return 0;
}