#include "stdafx.h"
#include <iostream>
#include <string.h>
#include <string>


using namespace std;

class term
{
	friend class polynomial;
private:
	int fact;
	int pow;
public:
	term(){ fact = 0; pow = 0; } //contractor (null)
	term(int x,int y){fact = x; pow = y;} //contractor (value)
	term (term &A){fact = A.fact; pow = A.pow;} //contractor (copy)

	//function
	void show()
	{
		cout<<fact<<"x^"<<pow;
	}

	//operator overloading
	friend ostream& operator << (ostream &out, term t)
	{
		t.show();
		return out;
	}
};

class polynomial
{
private:
	term cell[20];
	int count;
	//add similar value to each other
	void clear()
	{
		for (int i=0;i<20;i++)
		{
			for(int j=i+1;j<20;j++)
			{
				if(cell[i].pow==cell[j].pow)
				{
					cell[i].fact=cell[i].fact+cell[j].fact;
					cell[j].pow=-1;
					cell[j].fact=0;
				}
			}
		}
	}
	//this function convert string math expersion to numbercial cell's value
	void analys(string exp)
	{
		exp = exp + '+'; //condition for checking the sentence is exist + in the en of each sentence - add + to last sentence

		int fnum=0;//find and save "First_NUMber" of the charcter searched
		int snum;//save "Save_NUMber" of the last charcter fined

		int temp=0; //for convert string to int
		bool pow_flag=false; //for check each number is factor and each one is pow
		bool sign_flag=true; //for negative numbers
		for(int i=0;i<exp.size();i++) //
		{
			if(exp[i]=='-')
			{
				sign_flag=false;
			}

			if((exp[i]!='+')&&(exp[i]!='-'))
			{
				if(exp[i]>47 && exp[i]<58)
				{
					temp = temp*10 + (exp[i]-48);
				}
				else if(pow_flag==false)
				{
					if(sign_flag==false)
					{
						temp=temp*-1;
					}
					cell[count].fact=temp;
					temp=0;
					pow_flag=true;
					sign_flag=true;
				}
			}
			else
			{
				if(i!=0) //for check fisrt character is -
				{
					cell[count].pow=temp;
					temp=0;
					pow_flag=false;
					count++;	
				}
			}

		}
		clear(); //Add similar sentence with each other
	}
	void insert(int fact,int pow)
	{
		if(count<20) //Prevent overflow, the "cell" array has 20 components
		{
			cell[count].fact=fact;
			cell[count].pow=pow;
			count++;
		}
	}
protected:
	int power(int num,int pow)
	{
		int result=1;
		for(int i=0;i<pow;i++){result*=num;}
		return result;
	}
public:
	//contractors
	polynomial(){count=0;}; //Null
	polynomial(string exp){count=0;analys(exp);}; //by Value
	polynomial (polynomial &A){count=0;for(int i=0;i<20;i++){cell[i].fact=A.cell[i].fact;cell[i].pow=A.cell[i].pow;}} //by Copy

	//function
	void show()
	{
		for(int i=0;i<20;i++)
		{
			if(cell[i].pow!=-1 && cell[i].fact!=0)//Not Null & zero
			{
				cout<<cell[i].fact<<"x^"<<cell[i].pow<<"+";
			}
		}
	}
	void set(string exp)
	{
		count=0;
		analys(exp);
	}


	//operator overloading
	polynomial operator +(polynomial temp)
	{
		for(int i=0;i<20;i++)
		{
			if(cell[i].pow==temp.cell[i].pow)
			{
				cell[i].fact+=temp.cell[i].fact;
				temp.cell[i].fact=0;
				temp.cell[i].pow=-1;
			}
		}

		for(int i=0;i<20;i++)
		{
			if(temp.cell[i].pow!=-1 && temp.cell[i].fact!=0)//Not Null & zero
			{
				cell[count].fact=temp.cell[i].fact;
				cell[count].pow=temp.cell[i].pow;
			}
		}
		return *this;
	}
	polynomial operator *(polynomial temp)
	{
		polynomial result;
		for(int i=0;i<20;i++)
		{
			for(int j=0;j<20;j++)
			{
				if(temp.cell[j].pow!=-1 && cell[i].pow!=-1)//Not Null
				{
					result.insert(cell[i].fact*temp.cell[j].fact,cell[i].pow+temp.cell[j].pow); //insert(fact,pow)
				}
			}
		}
		return result;
	}
	polynomial operator -(polynomial temp)
	{
		for(int i=0;i<20;i++)
		{
			if(cell[i].pow==temp.cell[i].pow)
			{
				cell[i].fact-=temp.cell[i].fact;
				temp.cell[i].fact=0;
				temp.cell[i].pow=-1;
			}
		}

		for(int i=0;i<20;i++)
		{
			if(temp.cell[i].pow!=-1 && temp.cell[i].fact!=0)//Not Null & zero
			{
				cell[count].fact=-1*temp.cell[i].fact;
				cell[count].pow=-1*temp.cell[i].pow;
			}
		}
		return *this;
	}
	polynomial operator =(polynomial temp)
	{
		for(int i=0;i<20;i++)
		{
			cell[i].fact=temp.cell[i].fact;
			cell[i].pow=temp.cell[i].pow;
		}
		return *this;
	}
	int operator ()(int input)
	{
		//this function return "int",if we want it could return "polynomial" or anything else
		int result=0;
		for(int i=0;i<20;i++)
		{
			if(cell[i].pow!=-1 && cell[i].fact!=0)//Not Null & zero
			{
				result+=cell[i].fact*power(input,cell[i].pow);
			}
		}
		return result;
	}
	term operator [](int input)
	{
		//this function return "term",if we want it could return anything else
		return cell[input];
	}
	friend ostream& operator << (ostream &out, polynomial temp)
	{
		temp.show();
		return out;
	}
	friend istream& operator >> (istream &in, polynomial &temp)
	{
		string exp;
		in>>exp;
		temp.set(exp);
		return in;
	}

};




int _tmain(int argc, _TCHAR* argv[])
{
	int selection=0;
	while(1)
	{
		cout<<"---------------- Select an option -------------"<<endl;
		cout<<"1- add polynomials"<<endl;
		cout<<"2- subtract polynomials"<<endl;
		cout<<"3- evaluation"<<endl;
		cout<<"4- access by index"<<endl;
		cout<<"5- multiply"<<endl;
		cout<<"0- exit"<<endl;
		cin>>selection;
		cout<<"-----------------------------------------------"<<endl;

		if(selection==1)
		{
			polynomial A,B;
			cout<<"Enter the first polynomial:"<<endl;
			cin>>A;
			cout<<"Enter the first polynomial:"<<endl;
			cin>>B;
			cout<<"result is: "<<A+B<<endl;
		}
		if(selection==2)
		{
			polynomial A,B;
			cout<<"Enter the first polynomial:"<<endl;
			cin>>A;
			cout<<"Enter the first polynomial:"<<endl;
			cin>>B;
			cout<<"result is: "<<A-B<<endl;
		}
		if(selection==3)
		{
			polynomial A;
			int b;
			cout<<"Enter the polynomial:"<<endl;
			cin>>A;
			cout<<"Enter the variable:"<<endl;
			cin>>b;
			cout<<"result is: "<<A(b)<<endl;
		}
		if(selection==4)
		{
			polynomial A;
			int b;
			cout<<"Enter the polynomial:"<<endl;
			cin>>A;
			cout<<"Enter the index:"<<endl;
			cin>>b;
			cout<<"result is: "<<A[b]<<endl;
		}
		if(selection==5)
		{
			polynomial A,B;
			cout<<"Enter the first polynomial:"<<endl;
			cin>>A;
			cout<<"Enter the first polynomial:"<<endl;
			cin>>B;
			cout<<"result is: "<<A*B<<endl;
		}
		if(selection==0)
		{
			system("pause");
			return 0;
		}
	}
	return 0;
}