This is what I have:
string decimal_to_binary(int n){
string result = "";
while(n > 0){
result = string(1, (char) (n%2 + 48)) + result;
n = n/2;
}
return result; }
This works, but it doesn't work if I put a negative number, any help?
3 Answers
Just
#include <bitset>
Then use bitset and to_string to convert from int to string
std::cout << std::bitset<sizeof(n)*8>(n).to_string();
It works for negative numbers too.
Comments
Well I would recommend calling a separate function for negative numbers. Given that, for example, -1 and 255 will both return 11111111. Converting from the positive to the negative would be easiest instead of changing the logic entirely to handle both.
Going from the positive binary to the negative is just running XOR and adding 1.
You can modify your code like this for a quick fix.
string decimal_to_binary(int n){
if (n<0){ // check if negative and alter the number
n = 256 + n;
}
string result = "";
while(n > 0){
result = string(1, (char) (n%2 + 48)) + result;
n = n/2;
}
return result;
}
1 Comment
Jeredriq Demas
can you do the same with 32 bit?
This works, but it doesn't work if I put a negative number, any help?
Check whether the number is negative. If so, call the function again with -n and return the concatenated result.
You also need to add a clause to check against 0 unless you want to return an empty string when the input is 0.
std::string decimal_to_binary(int n){
if ( n < 0 )
{
return std::string("-") + decimal_to_binary(-n);
}
if ( n == 0 )
{
return std::string("0");
}
std::string result = "";
while(n > 0){
result = std::string(1, (char) (n%2 + 48)) + result;
n = n/2;
}
return result;
}
nand take appropriate action. What do you want the function to do with negative values?nis negative thenwhile (n > 0)fails to enter and so you return an empty string. Is that what you intended? It would be better to post a MCVE that produces some output, and explain how the output differs from what you wanted.n