C++ Hailstone Sequence

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Summary:

Very basic, bare-bones. Can calculate pretty high, but sorta breaks if a certain value is exceeded. Optimizations welcome.

C++ Hailstone Sequence

Musicrafter 10 Feb 2015 00:12

#include<iostream>

using namespace std;

int main(int o, int c)
{
    cout<<"The Hailstone Sequence"<<endl;
    for( ; ; )
    {
    cout<<"Pick any number. " <<endl;
    cin>> o;
    cin.ignore();
    cout<<"Your number is: "<< o <<endl;
    cout<<"The sequence generated will be displayed below."<<endl;
    // Code to go through the "hailstone sequence"
    c = 0;
    while ((o/2 >= 1) and ((o * 3)+1 >= 1))
    {
    if (o % 2 == 0)
    {
          o = o/2;
          cout<<" "<<o;
          c = c+1;
          if (c % 7 == 0)
          {
          cout<<""<<"\n";
          }
          if (o == 1)
          break;
    }
    if (o % 2 != 0)
    {
          o = (o * 3)+1;
          cout<<" "<<o;
          c = c+1;
          if (c % 7 == 0)
          {
          cout<<""<<"\n";
          }
          if (o == 1)
          break;
    }
    }
    cout<<endl<<"The sequence produced the following amount of numbers: "<<c<<endl;
    system("pause");
}
}

Re: C++ Hailstone Sequence

jonbush 10 Feb 2015 00:48

The while loop can be optimized to this:

c = 0;
while(o > 1){            //If only one step is performed per loop, the check can be simplified
    if(o % 2 == 0){      //Check if the number is even
        o /= 2;
    } else {             //If the number is not even, it must be odd - so we don't have to check again
        o = o * 3 + 1;
    }
    c++;                 //Increment the value of c by one
    cout<<" "<<o;
    if(c % 7 == 0){      //This makes a new line after every seven steps
        cout<<""<<"\n";
    }
}

You can also use while(true) instead of for(;;)
You could also use long c instead of int c so that it will work with much larger numbers

Last edited on 10 Feb 2015 00:56 by jonbush Show more

Re: C++ Hailstone Sequence

Timtech 11 Feb 2015 01:56

for(;;) is shorter than while(true)

Re: C++ Hailstone Sequence

jonbush 11 Feb 2015 02:34

The number of characters does not matter since they both compile into exactly the same thing.

Last edited on 11 Feb 2015 02:35 by jonbush Show more

Re: C++ Hailstone Sequence

12Me21 11 Feb 2015 16:16

while 1
If remainder(N,2
then
3N+1->N
else
N/2->N
end
disp N
end