题目描述

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

输入格式

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​N1 N2 a​N​2 … NK aNK
where K is the number of nonzero terms in the polynomial, Ni and aNi (i=1,2,⋯,K) are the exponents and coefficients, respectively. It is given that 1≤K≤10, 0≤NK<⋯<N2<N​1≤1000.

输出格式

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.

输入样例

2 1 2.4 0 3.2
2 2 1.5 1 0.5

输出样例

3 3 3.6 2 6.0 1 1.6

AC代码

#include <iostream>
#include <cstdio>
#include <algorithm>
using namespace std;

struct node{
	int e; //指数 
	double c; //系数 
}A[11], B[11];

int main(){
	int k1, k2;
	double C[10010] = {0}; //下标为指数，值为系数 
	int ex;
	double co;
	cin>>k1;
	for(int i = 0; i < k1; i++)
		cin>>A[i].e>>A[i].c;
	cin>>k2;
	for(int i = 0; i < k2; i++)
		cin>>B[i].e>>B[i].c;
	int max = A[0].e + B[0].e; //最大系数 
	for(int i = 0; i < k1; i++){
		for(int j = 0; j < k2; j++){
			ex = A[i].e + B[j].e;
			co = A[i].c * B[j].c;
			C[ex] += co;
		}
	}
	int cnt = 0; //非零项数
	for(int i = max; i >= 0; i--) 
		if(C[i] != 0) cnt++;
	cout<<cnt;
	for(int i = max; i >= 0; i--){
		if(C[i] != 0)
			printf(" %d %.1f", i, C[i]);
	}
	return 0;
}