【PAT甲级】【1002】 A+B for Polynomials (25分)

问题描述：

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:

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.

Output Specification:

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

 

问题解析：

•  对应多项式的项数可以设定数组，每一项都可一一对应数组中的单元，最后将数组中值不为零的有效单元计数输出即可。

AC代码：

#include<iostream>
#include<string>
#include<iomanip>
using namespace std;
int main() {
	int k, n = 0, t;
	double p[1005] = { 0 }, a;
	for (int i = 0; i < 2; i++) {
		cin >> k;
		for (int j = 0; j < k; j++) {
			cin >> t >> a;
			if (p[t] == 0)n++;
			p[t] += a;
			if (p[t] == 0)n--;
		}
	}
	cout << n;
	for (int i = 1004; i >= 0; i--) {
		if (p[i] != 0)cout << " " << i << " "<<fixed<<setprecision(1)<< p[i];
	}
	return 0;
}