解法一：模拟

模拟多项式乘法的运算过程，注意系数为0的项。

import java.io.*;
public class Main {
    private static float[] A = new float[1005];
    private static float[] B = new float[1005];
    private static float EXP = 1e-5f;
    public static void main(String[] args) throws IOException {
        StreamTokenizer in = new StreamTokenizer(new BufferedReader(new InputStreamReader(System.in)));
        PrintWriter out = new PrintWriter(new OutputStreamWriter(System.out));
        float[] A = new float[1005];
        float[] B = new float[1005];
        float[] C = new float[2010];
        read(in, A);
        read(in, B);
        for (int i = 0; i < A.length; ++i) {
            for (int j = 0; j < B.length; ++j) {
                C[i + j] += A[i] * B[j];
            }
        }
        int ans = 0;
        for (float v : C) {
            if (!equalZero(v)) {
                ++ans;
            }
        }
        out.print(ans);
        for (int i = C.length - 1; i >= 0; --i) {
            if (!equalZero(C[i])) {
                out.printf(" %d %.1f", i, C[i]);
            }
        }
        out.println();
        out.flush();
    }
    private static boolean equalZero(float f) {
        if (Math.abs(f) < EXP) {
            return true;
        }
        return false;
    }
    private static void read(StreamTokenizer in, float[] arr) throws IOException {
        in.nextToken();
        int len = (int) in.nval;
        for (int i = 0; i < len; ++i) {
            in.nextToken();
            int exponent = (int) in.nval;
            in.nextToken();
            float coef = (float) in.nval;
            arr[exponent] = coef;
        }
    }
}