[PAT甲级]1002 A+B for Polynomials详细题解+AC代码

[PAT甲级]1002 A+B for Polynomials

---

以下所述均为个人理解，如有错误，还望指正

---

题目

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:

$K$ N1N_1N1​ aN1a_{N_1}aN1​​ N2N_2N2​ aN2a_{N_2}aN2​​ ... NKN_KNK​ aNKa_{N_K}aNK​​

where $K$ is the number of nonzero terms in the polynomial, NiN_iNi​ and aNia_{N_i}aNi​​ ($i=1,2,\cdots ,K$) are the exponents and coefficients, respectively. It is given that $1\le K\le 10$，0≤NK<⋯<N2<N1≤10000 \le N_K < \cdots < N_2 < N_1 \le 10000≤NK​<⋯<N2​<N1​≤1000.

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.

---

题解：数组

利用res数组来表示相加的得到的多项式

#include <bits/stdc++.h>
using namespace std;
double res[1010]={0};
int main()
{
    int m, n;
    int exp;    // 指数
    double coe; // 系数
    cin >> m;
    for (int i = 0; i < m; i++)
    {
        cin >> exp >> coe;
        res[exp] += coe;
    }
    cin >> n;
    for (int i = 0; i < n; i++)
    {
        cin >> exp >> coe;
        res[exp] += coe;
    }
    int num = 0;
    for (int i = 1009; i >= 0; i--)
    {
        if (res[i] != 0)
            num++;
    }
    if (num == 0)
        cout << 0;
    else
    {
        cout << num;
        for (int i = 1009; i >= 0; i--)
        {
            if (res[i] != 0)
            {
                cout << " "<<i<<" "<<fixed <<setprecision(1) << res[i];
            }
        }
    }
    cout << endl;
}

---

AC结果：

---