1002 A+B for Polynomials (25分)

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 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​​​​ (,) are the exponents and coefficients, respectively. It is given that 1，0.

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

题解：用C++写了两次只通过了部分数据额，最后看别人的博客是用C语言来写的，确实，用C++来控制输入输出的格式不太好控制。

#include<iostream>
 
using namespace std;
 
int main() {
    float a[1001] = {0};
    int k;
    int exp;
    float coe;
 
    cin >> k;
    for(int i = 0; i < k; ++i) {
        cin >> exp >> coe;
        a[exp] += coe;
    }
 
    cin >> k;
    for(int i = 0; i < k; ++i) {
        cin >> exp >> coe;
        a[exp] += coe;
    }
 
    int count = 0;
    for (int i = 0; i < 1001; ++i) {
        if (a[i] != 0) count++;
    }
 
    cout << count;
    for (int i = 1000; i >= 0; --i) {
        if (a[i] > 0)
            cout << " " << i << " " << a[i];
    }
 
}

　　

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2021-01-28

Python列表表达式：[ expression for i in iterable ]

poly = [0 for _ in range(1001)]

按照习惯，有时候单个独立下划线是用作一个名字，来表示某个变量是临时的或无关紧要的。

例如，在下面的循环中，我们不需要访问正在运行的索引，我们可以使用“_”来表示它只是一个临时值

poly = [0 for _ in range(1001)]
 
def add():
    global poly
    line = input().split()[1:]
    i = 0
    while i < len(line) - 1:
        poly[int(line[i])] += float(line[i + 1])
        i += 2
 
add()
add()
 
count = 0
for i in range(1000, -1, -1):
    if poly[i] != 0:
        count += 1
 
print(count, end='')
for i in range(1000, -1, -1):
    if poly[i] != 0:
        print(" %d %.1f" % (i, poly[i]), end='')