Finding location of character in input2 from input1 - c++

Question

Important note: string (C++ object) and any other library such as array or vectors that could store unlimited characters cannot be used.
For my question:
We are given input 1, which is a sentence of unlimited characters. eg. Life is Beautiful.
Input 2: character who's location we have to find using the reference point (the middle character in input 1 after it is sorted and repeating characters are deleted) taken as zero. eg. fee.
An example:
Input 1: Life is beautiful
Input 2: see
Output: 2, -2, -2
Explanation: So firstly, we remove any spaces from input 1 and make all lowercase, then sort it in ascending order after which we find the reference letter (For above example, it's 'i'). We remove the repeating characters and then finally, put positions to character in input 1.
Example 2
Input 1: abcde
Input 2: aad
Output: -2, -2, 1
If the input 2 contains reference point, then the code returns zero.
Eg.
An example:
Input 1: abcde
Input 2: cab
Output: 0
The input1 is always odd and input2 is always 10 character max.
The problem I have is that I am not sure how to store these inputs without using strings, array etc. And even if I know how to store them, I cannot compare the inputs like input1[1] = input2[1] because we cannot use arrays/strings.
Is list an useful option with regards to important note?
I have mostly done it with the use of array but not sure how to approach it without the array. I tried to loop a character but it only stores the first character.
My practice code:
#include <iostream>
using namespace std;
int main() {
char input1;
for(int i =0; i < 3; i++ ) //for chacking whether the loops work or not.
{
cin >> input1;
}
cout<< input1;
char input2;
}
Please add any relevant tags.
I hope all the edits help.

Answer 1

KushanMehta proposed a C-ish solution. A more C++ one would be to implement a class wrapping a dynamic array of elements. In C++ it could be:
template <class T>
class MyArr {
protected:
T *arr; // a pointer to the dynamic array
size_t len; // the used length
size_t capacity; // the allocated capacity
...
As it contains a pointer to dynamic array, you cannot rely on default members, and should implement copy and move constructor and assignation operator and a destructor.
In order to be able to use all the goodies of C++ algorithm library, you should declare [c]begin() and [c]end() functions pointing to beginning of array and one past last element.
const T* cbegin() const {
return arr;
}
const T* cend() const {
return arr + len;
}
Then you need a subclass for characters implementing some methods to convert all characters to lower case and remove spaces, sort the array and remove duplicates. You should write io specializations for operator << and >> to be able to input strings from stdin and output them
The MyArr class can be used directly to store the resul value: just derive a specialization for int elements and implement the required specifications.
That may not be really easy, but you will learn C++ that way (not C)

Answer 2

You could do one thing to store the sentences by the use of dynamic memory for each character (sounds absurd but it is the only possible thing without actually worrying about the size of the input)
Meaning you take input till the user wants, in the meanwhile you can use malloc and realloc() for each new character, incrementing the size of your pointer to char for every new character.
(This is probably the way vector etc works on the naive level - not sure of this though)
Code snippet for the same:
#include <iostream>
#include<cstdlib>
#include<cstring>
using namespace std;
int main() {
char temp;
char *sentence = (char*) malloc(2*sizeof(char));
int counter = 0;
while( cin>>temp ){
sentence[counter++] = temp;
sentence = (char*) realloc(sentence, (counter+2)*sizeof(char));
}
sentence[counter] = '\0';
cout<<"The sentence is"<<endl<<strlen(sentence)<<endl<<sentence;
}