#include <stdio.h>
#include <malloc.h>
#include <string.h>
#include <deque>
using namespace std;
void addstrings(char **first,char *second) {
	int size = strlen(*first)+strlen(second);
	char *temp = new char[size+1];
	strcpy(temp,*first);
	strcpy(temp+strlen(*first),second);
	delete [] *first;
	*first=temp;
}
 
int compress(char *file,int level,int *additional=NULL) {
	int ret=0;
	FILE *thefile=fopen(file,"r");
	if (thefile) {
		int filesize=0;
		while (fgetc(thefile)!=EOF) filesize++;
		if (filesize%level) {
			ret=2;
			if (additional) *additional=filesize;
		} else {
			printf("Size of file: %d\n",filesize);
			rewind(thefile);
			char *temp = new char[filesize];
			fread(temp,filesize,1,thefile);
			int temp2;
			int temp3;
			deque<char*> table;
			char *tempstring=NULL;
			bool found=false;
 
			for (temp2=0;temp2<filesize;temp2+=level) {
 
				tempstring = new char[level+1];
				for (temp3=0;temp3<level;temp3++)
					tempstring[temp3]=temp[temp2+temp3];
				tempstring[temp3]=0;
				for (temp3=0;temp3<table.size();temp3++)
					if (strcmp(table[temp3],tempstring)==0) {
						found=true;
						break;
					}
				if (!found) table.push_back(tempstring);
			}
			char *tempfilestring = new char[strlen(file)+1];
			strcpy(tempfilestring,file);
			addstrings(&file,".compressed");
			fclose(thefile);
			thefile = fopen(file,"wb+");
			if (thefile) {
				fprintf(thefile,"%d\n",table.size());
				for (temp2=0;temp2<table.size();temp2++) 
					fprintf(thefile,"%d%s\n",temp2,table[temp2]);
				for (temp2=0;temp2<filesize;temp2+=level) {
					tempstring = new char[level+1];
					for (temp3=0;temp3<level;temp3++)
						tempstring[temp3]=temp[temp2+temp3];
					tempstring[temp3]=0;
					for (temp3=0;temp3<table.size();temp3++)
						if (strcmp(tempstring,table[temp3])==0) {
							fprintf(thefile,"%d",temp3);
							break;
						}
				}
				fclose(thefile);
			}
			else ret = 3;
			delete [] temp;
			for (temp2=0;temp2<table.size();temp2++)
				delete [] table[temp2];
			table.clear();
		}
	} else ret = 1;
	return ret;
}
int main(void) {
	char *buffer = new char[256];
	int compression = 0;
	int result=0;
	while (compression<256) buffer[compression++]=0;
	printf("What file?\n");
	fgets(buffer,255,stdin);
	buffer[strlen(buffer)-1]=0;
	printf("Compression level?\n");
	scanf("%d",&compression);
	switch (compress(buffer,compression,&result)) {//Get file and level of compression from above, and call compress function
	case 0: printf("File compressed.\n");break;
	case 1: printf("Couldn't open file.\n");break;
	case 2: printf("Invalid compression level. Level must divide evenly into file size. Filesize was %d\n",result);break;
	case 3: printf("Error creating new file to put compressed information in. File name was %s.compressed.",buffer);break;
	}
	delete [] buffer;
	return 0;
}