hello everyone
i am a fresh man in this site ... and i'm really pleased joining this lovely 'n useful one
well .. i made a program in c++ which is all about natural merge sort on files , since i want to sort my file which contains a randomly generated words (100 , 1000 .... words , according to Nmax value)
so .. i store my data in the file then call the merge sort function
but the problem is that when my data get bigger(i.e. more than 100 words) my program does a partial sorting on'em and it does not print the file in the end at all.. and i think it gets into an infinite loop cuz it does not end successfully ....... so i'm really astonished why!! cuz i'm almost sure that my program is bug-free
so please guyz help me ... and thank you in advance
here is my program bros:
#include<iostream>
using namespace std;
#include<fstream>
#include<ctime>
#include<string>
int Nmax = 1000;
fstream myfile;
bool compare(char w1[6], char w2[6])
{
string s1 = w1, s2 = w2;
if (s1 > s2)
return true;
else
return false;
}
void distribute(fstream& f1, fstream& f2)
{
string wrd;
char w[6];
myfile.read(w,6);
do
{
f1.write(w,6);
wrd = w;
myfile.read(w,6);
while ((!myfile.eof())&&(w > wrd))
{
f1.write(w,6);
wrd = w;
myfile.read(w,6);
}
if (!myfile.eof())
{
f2.write(w,6);
wrd = w;
myfile.read(w,6);
while ((!myfile.eof())&&(w > wrd))
{
f2.write(w,6);
wrd = w;
myfile.read(w,6);
}
}
} while(!myfile.eof());
}
int merge(fstream& f1, fstream& f2)
{
char w1[6], w2[6];
string wrd;
bool end_sequence ;
int nb_sequence = 0;
f1.read(w1,6);
f2.read(w2,6);
while ((!f1.eof())&&(!f2.eof()))
{
end_sequence = false;
do
{
if (compare(w2,w1))
{
myfile.write(w1,6);
wrd = w1;
f1.read(w1,6);
if (( wrd > w1)||(f1.eof()))
{
wrd = w2;
myfile.write(w2,6);
f2.read(w2,6);
while ((!f2.eof())&&(w2 > wrd))
{
myfile.write(w2,6);
wrd = w2;
f2.read(w2,6);
}
end_sequence = true;
}
}
else
{
myfile.write(w2,6);
wrd = w2;
f2.read(w2,6);
if ((wrd > w2)||(f2.eof()))
{
wrd = w1;
myfile.write(w1,6);
f1.read(w1,6);
while ((!f1.eof())&&(w1 > wrd))
{
myfile.write(w1,6);
wrd = w1;
f1.read(w1,6);
}
end_sequence = true;
}
}
}while (!end_sequence);
nb_sequence++;
}
while (!f1.eof())
{
wrd = w1;
myfile.write(w1,6);
f1.read(w1,6);
while ((!f1.eof())&&(w1 > wrd))
{
myfile.write(w1,6);
wrd = w1;
f1.read(w1,6);
}
nb_sequence++;
}
while (!f2.eof())
{
wrd = w2;
myfile.write(w2,6);
f2.read(w2,6);
while ((!f2.eof())&&(w2 > wrd))
{
myfile.write(w2,6);
wrd = w2;
f2.read(w2,6);
}
nb_sequence++;
}
return nb_sequence;
}
void Natural_mergeSort()
{
int nb_sequence;
fstream t1, t2;
do
{
myfile.open("file1.bin", ios::binary|ios::in);
t1.open("file2.bin", ios::binary|ios::out);
t2.open("file3.bin", ios::binary|ios::out);
t1.clear();
t2.clear();
if (!myfile)
{
cerr<<"file1 can not be opened"<<endl;
exit(1);
}
distribute(t1, t2);
myfile.close();
t1.close();
t2.close();
myfile.open("file1.bin", ios::binary|ios::out);
myfile.clear();
t1.open("file2.bin", ios::binary|ios::in);
t2.open("file3.bin", ios::binary|ios::in);
if (!t1)
{
cerr<<"file2 can not be opened"<<endl;
exit(1);
}
if (!t2)
{
cerr<<"file3 can not be opened"<<endl;
exit(1);
}
nb_sequence = merge(t1, t2);
myfile.close();
t1.close();
t2.close();
} while (nb_sequence!=1);
}
int main()
{
myfile.open("file1.bin", ios::binary|ios::out);
myfile.clear();
if (!myfile)
{
cerr<<"file could not be opened"<<endl;
exit(1);
}
char word[6];
srand(time(0));
int j, length, i, Cascii;
j = 1;
while (j<= Nmax)
{
length = 1+rand()%5;
for(i=0; i<length; i++)
{
Cascii= 97+rand()%25;
word[i] = Cascii;
}
word[i] = '\0';
cout<<word<<endl;
myfile.write(word,6);
j++;
}
myfile.close();
cout<<"*************"<<endl;
Natural_mergeSort();
myfile.open("file1.bin", ios::binary|ios::in);
while (!myfile.eof())
{
myfile.read(word,6);
cout<<word<<endl;
}
myfile.close();
return 0;
}
