【PAT甲级】 1009 Product of Polynomials

【PAT甲级】 1009 Product of Polynomials

原题

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 N_K a_NK

where K is the number of nonzero terms in the polynomial,N_i和a_Ni(i=1,2,⋯,K) are the exponents and coefficients, respectively. It is given that 1≤K≤10, 0≤N_K≤…≤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 1:

    2 1 2.4 0 3.2
    2 2 1.5 1 0.5

Sample Output 1:

    3 3 3.6 2 6.0 1 1.6

思路

题目要求

给定两个多项式，算多项式的乘法。

题目分析

1. 格式：无多余空格，小数点后保留一位；
2. 乘法和加减法不同，需要注意A多项式的每一项都要和B多项式的每一项相乘；
3. 和前面多项式的题目很像，也是用空间换时间，但是B多项式输入时需要计算后再存储；

易错点

1. 次数一样项数要记得相加；
2. double再scanf中是%lf；

参考代码如下

#include <iostr