c language implementation of the file data read into an array

1.txt

1 2 3 4 5 6 7 8 9 10
1 2 3 4 5 6 7 8 9 10

2.txt

1 2 3 4 5
2 3 4 5 6
4 5 6 7 8

Program code:

// C++ Read the text into the array .cpp :  Define the entry point for the console application. 
//

#include "stdafx.h"

int readfile1D()
{
	char a[100];
	int i;
	FILE *fp = fopen("1.txt","r");
	if(fp == NULL)
	{
		printf(" Invalid file read .\n");
		return -1;
	}
	for(i = 0; !feof(fp); i++)
		fscanf(fp, "%d", &a[i]);
	
	fclose(fp);

	for(i=0; i < 20; i++)
		printf("%d ", a[i]);
	printf("\n");

	return 0;
}

int readfile2D()
{
	int a[3][5];
	int i,j;
	FILE* fp = fopen("2.txt","r");
	if(fp == NULL)
	{
		printf(" The file is invalid ");
		return -1;
	}
	for(i=0; i<3; i++)
	{
		for(j=0; j<5; j++)
		{
			fscanf(fp,"%d",&a[i][j]);
		}
		//fscanf(fp,"\n");  Don't let it be 
	}

	fclose(fp);
	
	for(i=0; i<3; i++)
	{
		for(j=0; j<5; j++)
			printf("%d ", a[i][j]);
		printf("\n");
	}
	printf("\n");

	return 0;
}

int _tmain(int argc, _TCHAR* argv[])
{
	
	readfile1D();
	readfile2D();
	return 0;
}