integer to bool array

Question

I want to encode the integer like 83 to binary code like 1100101 what is the fastest way to do that? now I'm using this code:

ToBinary(int size, int value) {  
    size--;  
    this->code = new bool[size];  
    int in = size;  
    while (in >= 0) {  
        if(pow(2, in) <= value) {  
        this->code[size-in] = pow(2, in);  
        value -= pow(2, in);  
        } else   
            this->code[size-in] = 0;  
        in--;  
    }  
}

That's a rather awkward way to do it. Simpler by far (and easier to understand) is to create a mask variable with 0x0001 in it and then shift that value one position at a time and AND with the input value. Test the result of the AND to set your bool or not. — Hot Licks
– Hot Licks, Commented Sep 16, 2012 at 14:19
for(int idx = 0; idx <= size; ++idx) { this->code[size - idx] = !!(value & (1 << idx)); } — user1233508
– user1233508, Commented Sep 16, 2012 at 14:19
You can also use either std::vector<bool> or better boost::dynamic_bitset<> — Slava Zhuyko
– Slava Zhuyko, Commented Sep 16, 2012 at 14:26
thx guys, helped, i have a dumb question :D how to vote as Useful comment :D? — Benas Radzevicius
– Benas Radzevicius, Commented Sep 16, 2012 at 16:03

user1675187 · Accepted Answer · 2012-09-16 14:23:12Z

3

You could take advantage of shifting using >> to make things a lot easier:

ToBinary(int size, int value) {
    int i = size;

    this->code = new bool[size];

    while(i--) {
        this->code[i] = (value >> i) & 1;
    }
}

(Or, to have it in the opposite order, this->code[size - i].)

answered Sep 16, 2012 at 14:23

user1675187

Sign up to request clarification or add additional context in comments.

Comments

Jonathan Seng · Accepted Answer · 2012-09-16 14:49:56Z

1

If you know the size at compile time, std::bitset<size> bits(value); will do what you want in its constructor.

answered Sep 16, 2012 at 14:49

Jonathan Seng

1,2197 silver badges20 bronze badges

Collectives™ on Stack Overflow

integer to bool array

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related