1009 Product of Polynomials (25 point(s))

1009 Product of Polynomials (25 point(s))

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 N​1​​ a​N​1​​​​ N​2​​ a​N​2​​​​ ... N​K​​ a​N​K​​​​

where K is the number of nonzero terms in the polynomial, N​i​​ and a​N​i​​​​ (i=1,2,⋯,K) are the exponents and coefficients, respectively. It is given that 1≤K≤10, 0≤N​K​​<⋯<N​2​​<N​1​​≤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>
using namespace std;
const int A_MAX = 1007;
const int R_MAX = 2007;
int main(void){
	int N,M,exp;
	double coe;
	double a[A_MAX]={0};
	double res[R_MAX]={0};
	scanf("%d",&N);
	for(int i=0;i<N;i++){
		scanf("%d%lf",&exp,&coe);
		a[exp]+=coe;
	}
	scanf("%d",&M);
	for(int i=0;i<M;i++){
		scanf("%d%lf",&exp,&coe);
		for(int i=0;i<A_MAX;i++){
			if(a[i]!=0){
				res[i+exp]+=a[i]*coe;
			}
		}
	}
	int r=0;
	for(int i=0;i<R_MAX;i++){
		if(res[i]!=0) {
			r++;
		}
	}
	printf("%d",r);
	for(int i=R_MAX-1;i>=0;i--){
		if(res[i]!=0){
			printf(" %d %.1f",i,res[i]);
		}
	}
	printf("\n");
	return 0;
}

https://pintia.cn/problem-sets/994805342720868352/problems/994805509540921344