PAT甲级1009测试案例有一个通不过，麻烦各位大佬给看看啦

Question

题目：
https://pintia.cn/problem-sets/994805342720868352/problems/994805509540921344
我的代码：

#include<iostream>
#include<map>
#include<iomanip>
using namespace std;

int main()
{
    map<int,double>poly1;
    map<int,double>poly2;

    int k1,k2,e1,e2;
    double c1,c2;
    cin>>k1;
    for(int i=0;i<k1;i++)
    {
        cin>>e1>>c1;
        poly1.insert(make_pair(e1,c1));
    }
    cin>>k2;
    for(int i=0;i<k2;i++)
    {
        cin>>e2>>c2;
        poly2.insert(make_pair(e2,c2));
    }

    map<int,double>result;
    int E;
    double C;

    map<int,double>::reverse_iterator iter1;
    map<int,double>::reverse_iterator iter2;

    for(iter1=poly1.rbegin();iter1!=poly1.rend();iter1++)
    {
        for(iter2=poly2.rbegin();iter2!=poly2.rend();iter2++)
        {
            E=iter1->first+iter2->first;
            C=iter1->second*iter2->second;

            if(C!=0&&result.find(E)==result.end())
            {
                result.insert(make_pair(E,C));
            }
            else if(C!=0&&result.find(E)!=result.end())
            {
                map<int,double>::iterator iterTemp;
                iterTemp=result.find(E);
                iterTemp->second+=C;
            }
        }
    }

    map<int,double>::reverse_iterator iter;
    cout<<result.size();
    for(iter=result.rbegin();iter!=result.rend();iter++)
    {
        cout<<" "<<iter->first<<" "<<fixed<<setprecision(1)<<iter->second;
    } 
    return 0;
}

结果：

Answer 1

输出结果时，里面可能存在C为0的情况也被算进去了，虽然每次排除了加0的情况。