[PAT甲級] 1002 A+B for Polynomials (25)
阿新 • • 發佈:2019-02-08
This time, you are supposed to find A+B where A and B are two polynomials.
Input
Each input file contains one test case. Each case occupies 2 lines, and each line contains the information of a polynomial: K N1 a~N1~ N2 a~N2~ ... NK a~NK~, where K is the number of nonzero terms in the polynomial, Ni and a~Ni~ (i=1, 2, ..., K) are the exponents and coefficients, respectively. It is given that 1 <= K <= 10,0 <= NK < ... < N2 < N1 <=1000.
Output
For each test case you should output the sum 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 to 1 decimal place.
Sample Input
2 1 2.4 0 3.2
2 2 1.5 1 0.5
Sample Output
3 2 1.5 1 2.9 0 3.2
一個使用額外O(1)空間並且時間複雜度為O(N1)的簡單解如下:
#include <iostream> #include <cstdio> #include <cstring> using namespace std; int main() { float poly[1000] = {0.0}; int n, expo, maxE = 0; float coeff; cin >> n; for (int i = 0; i < n; i ++) { cin >> expo >> coeff; poly[expo] += coeff; if (maxE < expo) maxE = expo; } cin >> n; for (int i = 0; i < n; i ++) { cin >> expo >> coeff; poly[expo] += coeff; if (maxE < expo) maxE = expo; } n = 0; for (int i = 0; i <= maxE; i ++) { if (poly[i] != 0) n ++; } cout << n; if (n != 0) cout << " "; for (int i = maxE; i >= 0; i --) { if (poly[i] != 0.0) { n --; printf("%d %.1f", i, poly[i]); //cout << i << " " << poly[i]; if(n != 0) cout << " "; } } return 0; }