PAT甲级 1002 A+B for Polynomials 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:

where is the number of nonzero terms in the polynomial, ​​ and are the exponents and coefficients, respectively. It is given that .

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，敬请斧正