qsort() 2d dynamic array

[anup30]

ascending sort. rows wont be sorted internally.
comparison of row n and row m:
if row[n][0] < row[m][0] row[n] precedes row[m]
if row[n][0] > row[m][0] row[m] precedes row[n]
if row[n][0] == row[m][0] compare row[n][1] and row[m][1] so on ...

// 
#include <iostream>
#include <cstdlib> // qsort
using namespace std;

const int row = 4;
const int col = 3;

int qCompare (const void *a1,const void *b1){ // ascending
	const int *a = (const int*)a1;
	const int *b = (const int*)b1;
	
	for(int i=0; i<col; i++){		
		if(a[i]<b[i]) return -1;
		else if (a[i]>b[i]) return 1;		
	}
	return 0;
}

int main () {

	int **arr;
	arr = new int*[row];
	for(int i=0; i<row; i++) {
		arr[i] = new int[col];
	}		
	
	arr[0][0]=5;  arr[0][1]=1;  arr[0][2]=1; 
	arr[1][0]=8;  arr[1][1]=4;  arr[1][2]=2; 
	arr[2][0]=7;  arr[2][1]=2;  arr[2][2]=3; 
	arr[3][0]=8;  arr[3][1]=2;  arr[3][2]=4; 
	
	cout << "initial array \n";
	for(int i=0; i<row; i++) {			
		for(int j=0; j<col; j++) {
			cout << arr[i][j] << " ";
		}	
		cout << "\n";
	}	
	cout << "\n";
		
	qsort(arr, row, col*sizeof(int), qCompare); ///
	
	cout << "after qsort \n";
	for(int i=0; i<row; i++) {			
		for(int j=0; j<col; j++) {
			cout << arr[i][j] << " ";
		}	
		cout << "\n";
	}	
	cout << "\n";	
	
return 0;
}

i think arr has been inaccessible after qsort calling.
how to fix it?

EDIT:
after sorting the correct arr should contain this:

5 1 1
7 2 3
8 2 4
8 4 2

[anup30]

solved.

// 
#include <iostream>
#include <cstdlib> // qsort
using namespace std;

const int row = 4;
const int col = 3;

int qCompare (const void *a1,const void *b1){ // ascending
	const int *a = *(const int**)a1;
	const int *b = *(const int**)b1;
	
	for(int i=0; i<col; i++){		
		if(a[i] != b[i]) return a[i]-b[i];				
	}
	return 0;
}


int main () {

	int **arr;
	arr = new int*[row];
	for(int i=0; i<row; i++) {
		arr[i] = new int[col];
	}		
	
	arr[0][0]=5;  arr[0][1]=1;  arr[0][2]=1; 
	arr[1][0]=8;  arr[1][1]=4;  arr[1][2]=2; 
	arr[2][0]=7;  arr[2][1]=3;  arr[2][2]=3; 
	arr[3][0]=8;  arr[3][1]=2;  arr[3][2]=4; 
	
	cout << "initial array \n";
	for(int i=0; i<row; i++) {			
		for(int j=0; j<col; j++) {
			cout << arr[i][j] << " ";
		}	
		cout << "\n";
	}	
	cout << "\n";
		
	qsort(arr, row, sizeof arr[0], qCompare); ///
	
	cout << "after qsort \n";
	for(int i=0; i<row; i++) {				
		for(int j=0; j<col; j++) {
			cout << arr[i][j] << " ";
		}	
		cout << "\n";
	}	
	cout << "\n";
	
	
return 0;
}