This time, you are supposed to find A×B where A and B are two polynomials.
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 ?? <?<N ?2 ?? <N ?1 ?? ≤1000.
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.
2 1 2.4 0 3.2 2 2 1.5 1 0.53 3 3.6 2 6.0 1 1.61 #include <iostream> 2 #include <stdio.h> 3 #include <map> 4 #include <algorithm> 5 #include <iterator> 6 7 8 using namespace std; 9 10 double a[30]; 11 double b[30]; 12 map<int, double, greater<int> > mp; 13 14 int main() 15 { 16 int ka, kb; 17 cin >> ka; 18 ka = 2*ka; 19 for(int i = 1; i <= ka; i++) 20 { 21 cin >> a[i]; 22 } 23 24 cin >> kb; 25 kb = 2*kb; 26 for(int i = 1; i <= kb; i++) 27 { 28 cin >> b[i]; 29 } 30 31 32 for(int i = 1; i <= ka; i+=2) 33 { 34 for(int j = 1; j <= kb; j+=2) 35 { 36 mp[a[i]+b[j]] += a[i+1]*b[j+1]; 37 if(mp[a[i]+b[j]] == 0) // 合并后系数有可能为0，此时要删去 38 mp.erase(a[i]+b[j]); 39 } 40 } 41 42 int Size = mp.size(); 43 printf("%d", Size); 44 for(auto iter = mp.begin(); iter != mp.end(); ++iter) 45 { 46 printf(" %d %.1f", iter->first, iter->second); 47 } 48 49 50 return 0; 51 }
PAT 1009 Product of Polynomials
原文：https://www.cnblogs.com/FengZeng666/p/12589807.html