1002 A+B for Polynomials (25)（25 分）

    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 a~N1~ N2 a~N2~ ... NK a~NK~, where K is the number of nonzero terms in the polynomial, Ni and a~Ni~ (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
乍看這道題很簡單,放進map一頓亂揍就行了,結果首次提交答案是部分正確.仔細觀看題意:要求保留一位小數.但是引數都是最多1位小數,怎麼會出現不是一位小數的情況呢?(float a = 0; float b = 0; float c= a+b; c輸出為0.0)
仔細想想,對了,計算機計算加減法的時候是採取的二進位制補碼計算的,所以二進位制並不能精確表示十進位制,所以計算的時候會出現一些差錯的.會帶一個小尾巴,比如0.10000000001