1009. Product of Polynomials

1009. Product of Polynomials (25)

时间限制

400 ms

内存限制

32000 kB

代码长度限制

16000 B

判题程序

Standard

作者

CHEN, Yue

This time, you are supposed to find A*B where A and B are two polynomials.

Input Specification:

Each input file contains one test case. Each case occupies 2 lines, and each line contains the information of a polynomial: K N1 a_N1 N2 a_N2 ... NK a_NK, where K is the number of nonzero terms in the polynomial, Ni and a_Ni (i=1, 2, ..., K) are the exponents and coefficients, respectively. It is given that 1 <= K <= 10, 0 <= NK < ... < N2 < N1 <=1000.

Output Specification:

For each test case you should output the product of A and B in one line, with the same format as the input. Notice that there must be NO extra space at the end of each line. Please be accurate up to 1 decimal place.

Sample Input

2 1 2.4 0 3.2
2 2 1.5 1 0.5

Sample Output

3 3 3.6 2 6.0 1 1.6

#include <iostream>
#include <fstream>
#include <vector>
#include <string>
#include <algorithm>
#include <map>
#include <stack>
#include <cmath>
#include <queue>
#include <set>


using namespace std;


class Term
{
public :
    int exponent;
    double coefficient;
};


bool operator< ( const Term &t1 , const Term &t2 )
{
    return t1.exponent > t2.exponent;
}

//bool operator== ( const Term &t1 , const Term &t2 )
//{
//    return t1.exponent == t2.exponent;
//}


class Polynomial
{
public :
    vector<Term> terms;

    void addTerm( const Term &term )
    {

        for( int i = 0 ; i < this->terms.size() ; ++i )
        {
            if( this->terms[i].exponent == term.exponent )
            {
                this->terms[i].coefficient += term.coefficient;
                if( this->terms[i].coefficient == 0 )
                {
                    this->terms.erase(this->terms.begin() + i);
                }
                return;
            }
        }

        this->terms.push_back(term);

    }


    Polynomial times( const Polynomial &poly )
    {
        Polynomial result;

        for( int i = 0 ; i < poly.terms.size() ; ++i )
        {
            for( int j = 0 ; j < this->terms.size() ; ++j )
            {
                Term term;
                term.exponent = this->terms[j].exponent + poly.terms[i].exponent;
                term.coefficient = this->terms[j].coefficient * poly.terms[i].coefficient;

                result.addTerm(term);
            }
        }

        return result;
    }



    void toString()
    {


        sort(this->terms.begin() , this->terms.end());
    
        printf("%d" , this->terms.size());

        for( int i = 0 ; i < this->terms.size() ; ++i )
        {
            printf( " %d %.1f" , this->terms[i].exponent , this->terms[i].coefficient );
        }
        
        cout << endl;
    }
};




int main()
{



    Polynomial p1;
    Polynomial p2;
    int n;
    int m;

    cin >> n;
    
    for( int i = 0 ; i < n ; ++i )
    {
        Term term;
        
        cin >> term.exponent >> term.coefficient;

        p1.addTerm(term);
    }

    cin >> m;

    for( int i = 0 ; i < m ; ++i )
    {
        Term term;
        
        cin >> term.exponent >> term.coefficient;

        p2.addTerm(term);
    }

    p1.times(p2).toString();

    return 0;
}