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1009. Product of Polynomials (25)——PAT (Advanced Level) Practise
1009. Product of Polynomials (25)
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 Input2 1 2.4 0 3.2 2 2 1.5 1 0.5Sample Output
3 3 3.6 2 6.0 1 1.6
代码如下:
#include <iostream> #include <map> using namespace std; int main() { map<int, float> m1, m2, m3; int k, n; float a; cin >> k; for (int i = 0; i < k; i++) { cin >> n >> a; m1[n] = a; } cin >> k; for (int i = 0; i < k; i++) { cin >> n >> a; m2[n] = a; } for (map<int, float>::iterator it1 = m1.begin(); it1 != m1.end(); it1++) { for (map<int, float>::iterator it2 = m2.begin(); it2 != m2.end(); it2++) { m3[it1->first + it2->first] += it1->second * it2->second; } } cout.setf(ios_base::fixed, ios_base::floatfield); cout.precision(1); for (map<int, float>::iterator it = m3.begin(); it != m3.end(); it++) { if (it->second == 0.0f) m3.erase(it); } cout << m3.size(); for (map<int, float>::reverse_iterator it = m3.rbegin(); it != m3.rend(); it++) { cout <<" "<< it->first << " " << it->second; } cout << endl; return 0; }
1009. Product of Polynomials (25)——PAT (Advanced Level) Practise