浙江大學PAT上機題解析之1009. Product of Polynomials (25)

1009. Product of Polynomials (25)時間限制  400 ms
記憶體限制  32000 kB
代碼長度限制  16000 B
判題程式    Standard作者    CHEN, Yue

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 N1 aN1 N2 aN2 ... NK aNK, where K is the number of nonzero terms in
the polynomial, Ni and aNi (i=1, 2, ..., K) are the exponents and coefficients, respectively.  It is given that 1 <= K <= 10, 0 <= NK < ... < N2 < N1 <=1000. 

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 <iostream>#include <vector>#include <algorithm>#include <iomanip>using namespace std;typedef struct Node{  int exp;//指數  float coe;//係數}Node;Node product(Node a,Node b){  a.exp = a.exp+b.exp;  a.coe = a.coe*b.coe;  return a;}bool compare(Node a,Node b){    return a.exp>b.exp;}int main(){  Node node;  int M,N;    vector<Node>  vec1,vec2,vec,vec3;  vector<Node>::iterator it1,it2;  cin>>M;  while(M--)  {    cin>>node.exp>>node.coe;    vec1.push_back(node);  }  cin>>N;  while(N--)  {    cin>>node.exp>>node.coe;    vec2.push_back(node);  }  for (it1=vec1.begin();it1!=vec1.end();it1++)  for (it2=vec2.begin();it2!=vec2.end();it2++)    {      Node  t = product(*it1,*it2);      if (t.coe !=0)            vec.push_back(t);          }    sort(vec.begin(),vec.end(),compare);  for (it1=vec.begin();it1!=vec.end();it1 =it2)    {      for (it2=it1+1;it2!=vec.end() && ((*it1).exp == (*it2).exp);it2++)           (*it1).coe +=(*it2).coe;    if ((*it1).coe !=0)    {      vec3.push_back(*it1);    }  } cout<<vec3.size();  for (it1=vec3.begin();it1!=vec3.end();it1++)     cout<<" "<<(*it1).exp<<" "<<fixed<<setprecision(1)<<(*it1).coe;  cout<<endl;   //   system("pause");  return 0;}