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

Input

Each input file contains one test case. Each case occupies 2 lines, and each line contains the information of a polynomial: K N1 aN1 N2 aN2 ... 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 < N1 <=1000.

Output

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

#include <iostream>
#include<map>
#include<iomanip>
#include<stdio.h>
using namespace std;

int main()
{
    map<int,double> polynomial;

    int n,input1;
    double input2;

        scanf("%d",&n);
        for (int i=0;i<n ;i++ ){
            cin>>input1>>input2;
          polynomial[input1]=input2;
        }

        scanf("%d",&n);
        for (int i=0;i<n ;i++ ){
        cin>>input1>>input2;
        if(polynomial.find(input1)==polynomial.end()){
          polynomial[input1]=input2;
        }
        else{
            polynomial[input1]=polynomial[input1]+input2;
        }
        if(polynomial[input1]==0)
            polynomial.erase(input1);
    }

    map<int,double>::reverse_iterator i;
    cout<<polynomial.size();
    for (i=polynomial.rbegin();i!=polynomial.rend();i++){
        cout<<" "<<i->first<<" "<<fixed<<setprecision(1)<<i->second; ////fixed表示小數點右邊有多少位數字
    }
    return 0;
}

糾結錯誤

1.當多項式系數相加為零時要把map中的項刪除
2.map默認從小到大，可以用逆向迭代器逆序輸出
3.不會用map可以用數組代替