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

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\[i\];  
}

}

---

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='')