PAT甲级1002解题报告及疑惑

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 $a_{N_{}i}(i=1,2,\cdots ,K)$ are the exponents and coefficients, respectively. It is given that $1\le K\le 10,0\le N_K<\cdots <N_2<N_1\le 1000$.

Output Specification:

For each test case you should output the sum 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 to 1 decimal place.

Sample Input:

2 1 2.4 0 3.2
2 2 1.5 1 0.5

Sample Output:

3 2 1.5 1 2.9 0 3.2

My Code

#include 
using namespace std;

void do_union(double exponents_all[]);

int main()
{
	int n, exponents;
	double coefficients;
	double exponents_all[1000] = { 0 };
	//int output_all[10];

	for (int i = 0; i < 2; i++) 
	{
		cin >> n;
		while (n != 0)
		{
			cin >> exponents >> coefficients;
			exponents_all[exponents] += coefficients;
			n--;
		}
	}
	do_union(exponents_all);
}

void do_union(double exponents_all[])
{
	int count = 0;
	for (int i = 999; i >= 0; i--)
	{
		if (exponents_all[i] != 0)
			count++;
	}
	cout << count;
	for (int j = 999; j >= 0; j--)
	{
		if (exponents_all[j] != 0)
			printf(" %d %.1f", j, exponents_all[j]);
	}
}

疑惑

• 我的代码提交之后，有一个样例没有通过，扣了两分，我感到非常疑惑。
  • 由于陈越姥姥并没有公布测试样例是什么，根据我的经验，可能是存在输入的系数为0的情况。
  • 根据题目，他并没有限制系数为0的情况，然而为了方法更简洁，我在void do_union(double exponents_all[])里的for循环将系数为0的情况跳过了。
  • 暂时没想到更简洁的方法，错了就错了吧。如果有朋友看出来问题，请斧正