pat 1002

1002 A+B for Polynomials (25分)

 

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​​​​ (,) are the exponents and coefficients, respectively. It is given that 1，0.

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

有一个坑点，系数为0的时候不能加入答案，也不能判断mp[*it]大于0，否则有一个测试点会出错

 

 

#include<bits/stdc++.h>

using namespace std;

map<int, double> mp;

set<int> s;

int main(){

    int k1,k2,i=0;

    cin >> k1;

    while(k1--){

        double a;

        int N;

        cin >> N >> a;

        s.insert(N);

        mp[N] += a;

    }

    cin >> k2;

    while(k2--){

        double a;

        int N;

        cin >> N >> a;

        s.insert(N);

        mp[N] += a;

    }

    for(auto& p:s){

        if(mp[p]!=0)//等于0的直接跳过

            i++;

    }

    printf("%d", i);

    set<int>::iterator it = s.end();

    do{

        it--;

        if(mp[*it]!=0)printf(" %d %.1lf", *it, mp[*it]);

    } while (it != s.begin());

    return 0;

}