PAT (Advanced Level) Practise：1002. A+B for Polynomials

【题目链接】

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

题意分析：

两个多项式加法，然后按指数项从高到低分别输出“指数 系数”。

提交代码：

 #include <stdio.h>
 #include <string.h>

 int main(void)
 {
     float a[+];
     float b[+];
     int i, cnt;
     int K, Nk;
     float aNk;

     memset(a, , sizeof(a));
     memset(b, , sizeof(b));

     scanf("%d", &K);
     for(i = ; i < K; i++)
     {
         scanf("%d %f", &Nk, &aNk);
         a[Nk] = aNk;
     }
     scanf("%d", &K);
     for(i = ; i < K; i++)
     {
         scanf("%d %f", &Nk, &aNk);
         b[Nk] = aNk;
     }

     cnt = ;
     for(i = ; i < sizeof(a)/sizeof(a[]); i++)
     {
         a[i] = a[i] + b[i];
         if(a[i] != 0.0)
             cnt++;
     }

     printf("%d", cnt);
     for(i = sizeof(a)/sizeof(a[]) - ; i >= ; i--)
     {
         if(a[i] != )
             printf(" %d %.1f", i, a[i]);
     }

     return ;
 }