1009. Product of Polynomials (25)

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<stdio.h>
#include<string.h>
#include<stdlib.h>

double str1[1001],str2[1001],ans[2002];
int main()
{
    int n,m,zi,xi,cnt=0;
    int i,j;
    scanf("%d",&n);
    for( i=0; i<n; i++)
    {
        scanf("%d",&zi);
        scanf("%lf",&str1[zi]);
    }
    scanf("%d",&m);
    for( i=0; i<m; i++)
    {
        scanf("%d",&zi);
        scanf("%lf",&str2[zi]);
    }
    for( i=0; i<1001; i++)
    {
        if( str1[i])
        {
            for( j=0; j<1001; j++)
                if( str2[j])
                    ans[i+j] += str1[i]*str2[j];
        }
    }
    for( i=0; i<2001; i++)
        if( ans[i])
            cnt++;
    printf("%d",cnt);
    for( i=2001; i>=0; i--)
    {
        if( ans[i])
            printf(" %d %.1f",i,ans[i]);
    }
    return 0;
}