1009 Product of 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 product 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 up to 1 decimal place.

Sample Input:

2 1 2.4 0 3.22 2 1.5 1 0.5

Sample Output:

3 3 3.6 2 6.0 1 1.6

#include
        
         using namespace std;typedef long long ll;#define maxnum 100005double a[1005] = {
      0};double b[1005] = {
      0};double c[maxnum] = {
      0};int main(){    int n;cin >> n;    int t;    for(int i=0;i < n;i++){        int x;double y;        cin >> x >> y;        a[x] = y;        if(!i)t = x;    }    int m;cin >> m;    int start;    for(int i=0;i < m;i++){        int x;double y;        cin >> x >> y;        b[x] = y;        if(!i) start = x;    }    for(int i=0;i < t+5;i++){        for(int j=0;j < start+5;j++){            c[i+j] += a[i]*b[j];        }    }    int cnt = 0;    for(int i=0;i < maxnum;i++)if(c[i])cnt++;    cout << cnt;    for(int i=maxnum-1;i>=0;i--){        if(c[i]) printf(" %d %.1lf",i,c[i]);    }    return 0;}
        

空间开的有点小炸，做了一下优化就好了，再一次理解错了提议，K<10，不一定就项系数<10，还好这题没出毒瘤卡边界数据，在超过1e5的地方直接放弃了。。