PAT甲级 1002 A+B for Polynomials （25 分) (数组下标模拟多项式加法)

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
​​ <⋯ ​2
​​ ​1
​​ ≤1000.

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

题意

每一行第一个数K代表这个多项式的项数，接下来有2K个数，每两个数代表多项式的阶数和前面的系数
给你这两个多项式计算这两个多项式的和输出和多项式有多少个非0项和以降序输出每一项的阶数和系数

思路

直接用double数组来表示多项式(看范围就1000，直接开大小为1000的数组就好了)，数组下标为多项式的阶数里面的内容是系数，直接对应下标的数相加就好了，然后倒着遍历整个数组就好了，注意一下最后一个多项式最后不是空格是回车就好了

#include 
using namespace std;
double a[1005];
int main()
{
    int k;
    scanf("%d",&k);
    for(int i=0;i=0;i--)
    {
        if(a[i]!=0)
            printf("%d %.1lf%c",i,a[i]," \n"[--cnt==0]);
    }
    return 0;
}