#include <stdio.h>
#include <ctype.h>
#include <conio.h>

char* find_const(int buf)
{
	int i, k, b;
	char *j;
	char buf_num[ 256 ];
	char buf_lit[ 256 ];
	char *buf_num_return;
	
	FILE *in;
	in=fopen("c:\input.txt","r");
	if(in == NULL) {
		printf ("error in opening of the file");
		return NULL;
	}
	while ((j = fgetc(in)) != EOF) {
		if (isdigit(*(j+b))) {
			buf_num[i] = j[b];
			i++;	b++;
		} else {
			*(buf_num[i]) = '\0';
			i++;
			if (k < buf) {
				buf_lit[k] = j[b];
				k++;	b++;
			}
		}
	}
	fclose(in);
	buf_num_return = (char*)calloc(buf+ [b]1 , sizeof(char));
	if(buf_num_return != NULL)
		strncpy(buf_num_return, buf_num,  3 *sizeof(char));
		
	return buf_num_return;
}

int main()
{
	int m, i;
	int buf;
	char *buf_num;
	
	clrscr();
	printf("enter value of buffer buf_lit");
	scanf("%d", &buf);
	buf_num = find_const(buf);
	if(buf_num == NULL) {
		printf("find_const() returned NULL\n");
		exit( 1 );
	}
	printf("values of buf_num:\n");
	for(m =  0 ; m < i; m++)
		printf("%c\n", *buf_num[m]);
	free(buf_num);
	getch();
}