1002 A+B for Polynomials (25 分)

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?????(,) are the exponents and coefficients,respectively. It is given that?1，0.

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

#include<iostream>
#include<cstdio>
#include<string.h>

using namespace std;
double a[1001] = { 0.0 };
char str[1000] = "",str1[100];//将str[100]扩大为1000，运行时错误便可以去掉
int main() {
    int n;
    cin >> n;
    int i;
    double j;
    while (n--) {
        cin >> i >> j;
        a[i] += j;
    }
    cin >> n;
    while (n--) {
        cin >> i >> j;
        a[i] += j;
    }
    int cnt = 0;
    for (i = 1000; i >= 0; i--) {
        if (a[i] != 0) {
            sprintf(str1," %d %0.1lf",i,a[i]);
            strcat(str,str1);
            cnt++;
        }
    }
    cout << cnt << str;
    return 0;
}