6 replies to this topic

[novera_monkey]

how to save a long long int (64 bit) in simply an int ?
i.e and int inputs values tht are very long and save them and then we have to multiply those values from one another.
we cannot use long from it , i.e we have to combine two 32 bit int to make a 64 bit .
we can use classes.

[artificial]

So, you aren't allowed to use "long long", right? You could use a struct instead that consists of two 32-bit integers.

struct MyInt64

{

  long nHighOrderQW; //QW = Quadword = 32 bit

  long nLowOrderQW;

};

Simply ask if there are more questions.

Greets,
artificial

Edited by artificial, 15 July 2010 - 02:38 AM.

[novera_monkey]

what further ?
how will we carry on with the program , please help me it it!!

[Ancient Dragon]

Same question posted on DaniWeb.

[zoranh]

artificial said:

So, you aren't allowed to use "long long", right? You could use a struct instead that consists of two 32-bit integers.

struct MyInt64
{
  long nHighOrderQW; //QW = Quadword = 32 bit
  long nLowOrderQW;
};

Simply ask if there are more questions.

Greets,
artificial

Lower part must be unsigned long or won't work. In this way you've lost one bit of information from original 64-bit signed integer - it had 63 bits of numeric information plus one bit for sign, while two longs have 62 bits of numeric information and two sign bits.

[TkTech]

This appears to be a homework question.

@Op: I'd advise you to look into arbitrary precision arithmetic. In particular, look at the theory and a very good example on LiteratePrograms.

[artificial]

zoranh said:

Lower part must be unsigned long or won't work.

Oh, yes, you're right. My bad. :)