#include <iostream>
#include <fstream>
#include <cstring>
 
using namespace std;
 
int main() {
    char * buffin = (char*)malloc(1024*4+4);//+4 prevents need for index out of range checks
    char * buffout = (char*)malloc(1024*4);
    char * bufftmp = (char*)malloc(1024*4);
 
    std::fstream file;
    file.open ("/uploads/tt.bin", std::fstream::in | std::fstream::binary);
    file.read(buffin,1024*4);
    file.close();
	buffin[1024*4+0]=buffin[1024*4-2]+1;buffin[1024*4+1]=buffin[1024*4-1]+1; //ensure last four bytes don't match
	buffin[1024*4+2]=buffin[1024*4-2]-1;buffin[1024*4+3]=buffin[1024*4-1]-1; //ensure last four bytes don't match
    file.open ("/myfiles/tt.rle", std::fstream::out | std::fstream::binary);
 
    char cur;
    int i=0;int o=0;
    buffout[o++]=0x01;//size 4kb
    buffout[o++]=0x01;//size of count values?
    int t;
    while (i<1024*4){ //low bytes
		if (buffin[i]!=buffin[i+2]){ //start of nonrepeating
			t=0;
			while ((i<1024*4) && (buffin[i+2]!=buffin[i+4]) && (t<127-1)) {bufftmp[t++]=buffin[i];i+=2;} //while not start of repeating
			bufftmp[t++]=buffin[i];i+=2;
			buffout[o++]=t;memcpy(buffout+o,bufftmp,t);o+=t;continue;
		} else { //start of repeating
			t=1;i+=2;
			while ((i<1024*4) && (buffin[i-2]==buffin[i]) && (t<127)) {t++;i+=2;} //while not start of repeating
			buffout[o++]=0x80|t;buffout[o++]=buffin[i-2];continue;
 
		}
 
    }
	buffout[o++]=0x00; //terminator
	buffout[o++]=0x02; //size of count values?
 
	i=1;
    while (i<1024*4){ //high bytes
		if (buffin[i]!=buffin[i+2]){ //start of nonrepeating
			t=0;
			while ((i<1024*4) && (buffin[i+2]!=buffin[i+4]) && (t<32767-1)) {bufftmp[t++]=buffin[i];i+=2;} //while not start of repeating
			bufftmp[t++]=buffin[i];i+=2;
			buffout[o++]=t>>8;buffout[o++]=0xff&t;memcpy(buffout+o,bufftmp,t);o+=t;continue;
		} else { //start of repeating
			t=1;i+=2;
			while ((i<1024*4) && (buffin[i-2]==buffin[i]) && (t<32767)) {t++;i+=2;} //while not start of repeating
			buffout[o++]=(t>>8)|0x80;buffout[o++]=0xff&t;buffout[o++]=buffin[i-2];continue;
 
		}
 
    }
	buffout[o++]=0x00; //terminator
	buffout[o++]=0x00; //terminator
 
    file.write(buffout,o);
    file.close();
    free(buffin);free(buffout);free(bufftmp);
    return 0;
}