Basic obfuscation program - c++

Question

#include<iostream>
#include<conio.h>
#include<math.h>
#include<vector>
#include<iterator>
#include<string>
using namespace std;
int main() {
int k=0;
string s;
cout<<"string ";
getline(cin,s); //taking in a string from the user
float n=s.size(); //storing size of string
int f=floor((sqrt(n))); //floor of square root of input string
int c=ceil((sqrt(n))); //ceiling
int m=f*c; //storing product of f and c
vector< vector<string> > vec(n<=m?f:++f, vector<string>(c)); //makes a 2d vector
//depending on user's
//string length
for(int i=0;n<=m?i<f:i<++f;i++) //looping acc to user's input and assigning
{
for(int j=0;j<c;j++) //string to a matrix
{
if(k<s.size())
{
vec[i][j]=s[k];
k++;
}
}
}
for(int j=0;j<c;j++) //printing the vector
{
{
for(int i=0;n<=m?i<f:i<++f;i++)
cout<<vec[i][j];
}cout<<" ";
}
getch();
}
It's not working for n>m as for a string of length 8 characters it makes a vector of 2*3 thus failing to enclose the whole string in the matrix and which is why I am using ternary so as to make a vector of bigger size when it encounters cases like these.
.So what am I doing wrong?
I'll just write the whole question.
One classic method for composing secret messages is called a square code. The spaces are removed from the english text and the characters are written into a square (or rectangle). The width and height of the rectangle have the constraint,
floor(sqrt(word)) <= width, height <= ceil(sqrt(word))
The coded message is obtained by reading down the columns going left to right. For example, the message above is coded as:
imtgdvs fearwer mayoogo anouuio ntnnlvt wttddes aohghn sseoau
Sample Input:
chillout
Sample Output:
clu hlt io

Answer 1

This won't fix your entire problem, but I still feel it is important. You seem to misunderstand how the ternary works. Let's observe one of its uses here:
for (int i = 0; n <= m ? i < f : i < ++f; i++) {}
// ^^^^^^^^^^^^^^^^^^^^^^^^ <--- not the intended outcome
This will not work because the returned side of the ternary does not "stick" itself in-place. In other words, neither i < f nor i < ++f will be put directly into the for-loop. Instead, it'll give you a value.
To see what it's really doing, you'll first need to understand that the ternary is just another way to do an if-else. The ternary above, put into if-else form, looks like this:
if (n <= m)
i < f; // left side of the ":"
else
i < ++f; // right side of the ":"
Let's break it down further:
i < f
This is doing a less-than comparison of i and f. So, depending on the individual values, you'll receive either a 0 (false) or a 1 (true).
So, in your for-loop, this will occur:
for (int i = 0; 1; i++) {}
// ^ <--- if comparison returns true
for (int i = 0; 0; i++) {}
// ^ <--- if comparison returns false
So, for your example, you'll need to find the value of f before the loop. You can use a ternary for that part, but only if you understand it. Otherwise, use another method to find f (the intended numerical value). Once you find it, then you can put i < f into the for-loop.