#include <stdio.h>
#include <stdlib.h>
#define	N_DATA	50000

int main ( void )
{
	int		i;
	int		data[N_DATA];
	FILE*	fp;

	fp = fopen ( "data.txt", "w" );

	for ( i=0; i < N_DATA; i++ )
	{
		data[i] = rand();
		fprintf ( fp, "%d\n", data[i] );
	}

	fclose ( fp );
}

Segmentation fault