1002 A+B for Polynomials （附测试点3456的坑）

题目：1002 A+B for Polynomials

This time, you are supposed to find

Input Specification:

Each input file contains one test case. Each case occupies 2 lines, and each line contains the information of a polynomial:

where

Output Specification:

For each test case you should output the sum of

Sample Input:

1 2	`2` `1` `2.4` `0` `3.2` `2` `2` `1.5` `1` `0.5`

Sample Output:

1	`3` `2` `1.5` `1` `2.9` `0` `3.2`

思路：

1、使用map

2、注意当底数为0的项不需要输出，当两个多项式相加结果为0时，直接输出0就好了。

测试样例：

1 2	`1` `0` `3.2` `1` `0` `-3.2`

输出：

0

代码：

#include<stdio.h>
#include<iostream>
#include<iomanip>
#include<ios>
#include<map>
using namespace std;
int main(){
    map<int, double> m;
    map<int, double>::reverse_iterator it;
    int k = 2,n,e,count = 0;
    double c;
    for(int i = 0; i < k; i++){
        cin>>n;
        for(int j = 0; j < n; j++){
            cin>>e>>c;
            m[e] += c;
        }
    }
    for(it = m.rbegin(); it != m.rend(); it++){
        if(it->second == 0){
            continue;
        }
        count++;
    }
    cout<<count;
    for(it = m.rbegin(); it != m.rend(); it++){
        if(it->second == 0){
            continue;
        }
        cout<<" "<<it->first<<" ";
        cout<<fixed<<setprecision(1)<<it->second;
    }
    return 0;
}