PTA-1009—— Product of Polynomials

题目:

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 3.2
2 2 1.5 1 0.5

Sample Output:

3 3 3.6 2 6.0 1 1.6

题目分析:

数学运算

代码:

 1 #include<iostream>
 2 #include<cstring>
 3 #include<algorithm>
 4 using namespace std;
 5 int k1,k2;
 6 int max1,max2;
 7 float list1[1001],list2[1001],list[2001];
 8 int main(){
 9     memset(list1,0,sizeof(list1));
10     memset(list2,0,sizeof(list2));
11     memset(list,0,sizeof(list));
12     cin>>k1;
13     max1=0;
14     for(int i=0;i<k1;i++){
15         int n;
16         cin>>n;
17         cin>>list1[n];
18         max1=max(max1,n);
19     }
20     cin>>k2;
21     max2=0;
22     for(int i=0;i<k2;i++){
23         int n;
24         cin>>n;
25         cin>>list2[n];
26         max2=max(max2,n);
27         for(int j=0;j<=max1;j++){
28             list[n+j]+=list1[j]*list2[n];
29         }
30     }
31     int count=0;
32     for(int i=0;i<=max1+max2;i++){
33         if(list[i]!=0){
34             count++;
35         }
36     }
37     cout<<count;
38     for(int i=max1+max2;i>=0;i--){
39         if(list[i]!=0){
40             printf(" %d %.1lf",i,list[i]);
41         }
42     }
43     return 0;
44 }

 

转载于:https://www.cnblogs.com/orangecyh/p/10286405.html