1002 A+B for Polynomials C++精确度问题

 

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​​​​ (i=1,2,⋯,K) are the exponents and coefficients, respectively. It is given that 1≤K≤10，0≤N​K​​<⋯

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

这道题用数组的方法来解决，只要是数据量不大，数据排列有规律。

 #include
#include
#include
#include
using namespace std;
int main()
{
    float a[1001];
    int  num, exp;
    float coe;
    for (int i = 0; i < 1001;i++)
        a[i] = 0.0f;
    cin >> num;
    while (num--)
    {
        cin >> exp >> coe;
        a[exp] += coe;
    }
    cin >> num;
    while (num--)
    {
        cin >> exp >> coe;
        a[exp] += coe;
    }
    int count = 0;
    for (int i = 0; i < 1001; i++)
    {
        if (a[i] != 0.0)
            count++;
    }
    cout << count;
    if (count != 0)
        cout << " ";
    for (int i = 1000; i >= 0; i--)
        if (a[i] != 0.0)
        {
            cout << i << " " <             count--;
            if (count != 0)
                cout << " ";
        }
    return 0;
}

其中，C++要控制精确到以为小数 首先需要头文件  

然后 输出之前setiosflags(ios::fixed)<