How to collapse integers in text file into single digit in the fastest time?

binary or text. what is the collapsing mechanism? an example:
1234567890
sum of digits = 45
sum of digits = 9
now the number is single digit so you stop.

i forgot..

the integers in the text file is in one line.. but it would be a long one to make it 10MB.. no space between the integers..

12347435794864982316498652189236598236593218659213865923659385698231659   -->>  all through the way..

collapse them in single digit (plus each integers until get single digit)

cheers

yeah jhshukla.. exactly like you said.. :)

Presumably your 10Mb of text is meant to have some format. How many characters represent each integer? Or do you simply want to pack two 4-bit digits into each byte to halve the size of the file?

So you could

#include <iostream>
#include <fstream>
#include <string>
#include <sstream>
using namespace std;

int main () {

    ifstream is ( "file.txt");
    string str;

    getline(is,str);

    while(str.size() != 1) {

        for ( int i = 0; i < str.size(); ++i) {

             n+=str[i]-'0';
        }

        stringstream ss;

        ss << n;

        str = ss.str();
    }

    cout << n << endl;

    return 0;
}

jkr:
...
n += str[i]-'0'
n %= 10;
...

jaydutt

>>n %= 10;

No, that's being taken of during the next round in the 'while()' loop.

yup. my bad.

hi jkr..

i'm having problem compiling your codes because my compiler said it was unable to open include file "sstream.h". I'm using Borland C++ version 5.02.

>> my compiler said it was unable to open include file "sstream.h"

There shouldn't be such a file - it is <sstream>, without a trailing .h extension. You might want to check if there's an updated STL version for your compiler at www.stlport.org

i put <sstream> without .h extension and that is the error msg.

i'll try to find the updated STL version you said (although i don't know what it is..:)

That's baiscally a bunch of header files to replace your STL an the one or the other library...

i try to install the updated STL but still cannot.. iguess the installion is not a success because it abit messy that i could not understand how to install..

so is there any way to solve this or if there is any other codings that can do the same function?
i like your coding because it short andunderstandable..but i cannot compile it..sorry

...
n += str[i]-'0'
n %= 10;
...

doesn't require sstream!

it give error now..

Error:  NONAME01.CPP(12,20):Could not find a match for 'std::getline(ifstream,std::basic_string<char,std::string_char_traits<char>,std::allocator<char>>)'

any other codings? Please..

Anyone please?

jkr? Any other ways?

did you try what I posted? I am not trying to prove jkr wrong but you should try everything that is posted here and that makes sense to you.

i've tried your version and posted the error up there..

Error:  NONAME01.CPP(12,20):Could not find a match for 'std::getline(ifstream,std::basic_string<char,std::string_char_traits<char>,std::allocator<char>>)'

If there any modification to be done?

i tried and it compiles and runs fine with MSVC++ 6.0.
try is.getline()

no prob with bcc either. here's command line output

C:\Documents and Settings\Jaydutt>bcc32 cpp.cpp
Borland C++ 5.5.1 for Win32 Copyright (c) 1993, 2000 Borland
cpp.cpp:
Warning W8012 cpp.cpp 17: Comparing signed and unsigned values in function main()
Turbo Incremental Link 5.00 Copyright (c) 1997, 2000 Borland

C:\Documents and Settings\Jaydutt>

Jaydutt

sorry Jaydutt.. i've tried.. but still got error..both bcc and msvc++..

can you please write here the whole coding with the changes you made? maybe i wrote the codes wrongly..i'm not so good in C++ even the basics one.. if possible for Borland C++ because i familiar wth Borland C++...i don't know how to detect the error if using MSVC++..it just show errors found but not pointed where the error is..maybe i'm the only one who do not know to use MSVC++ :)

thanks

you must use these headers:

<iostream> --->  <iostream.h>
<fstream>  --->  <fstream.h>
<string>     --->  <string.h>
<sstream> --->  <strstrea.h> or <strstream.h>

have a good programming day.

50+/-10 points to jkr
50+/-10 points to jhshukla
delete the rest of points.