PAT-1002 A+B for Polynomials 解答(C++/Java/python)

1.Description：

2.Example：

Input:
2 1 2.4 0 3.2
2 2 1.5 1 0.5
output:
3 2 1.5 1 2.9 0 3.2

3.Solutions:

C++ Version:

#include<iostream>
#include<map>
#include<vector>
using namespace std;

int main() {
    map<int, float> polynomial;
    for (int i = 0; i < 2; ++i) { //按行存入map里面
        int n;
        scanf("%d", &n); //读取K值
        for (int i = 0; i < n; ++i) {
            int exp;
            float cof;
            scanf("%d%f", &exp, &cof); //读系数和读值
            polynomial[exp] += cof; //将对应系数值存入map中
        }
    }
    vector<pair<int, float> > output; //遍历map将值不等0的元组存入数组里
    for(auto it = polynomial.rbegin(); it != polynomial.rend(); it++) {
        if(it->second != 0) 
            output.emplace_back(it->first, it->second);
    }

    printf("%d", output.size());
    for (int i = 0; i < output.size(); ++i) { //格式化输出
        printf(" %d %.1f", output[i].first, output[i].second);
    }
    return 0;
}

Java Version:

import java.util.Scanner;

/**
 * Created by SheepCore on 2020-2-26
 *
 */
public class Main {
    public static void main(String[] args) {
        final int NUM = 2;
        final int MAX = 1000;
        float[] poly = new float[MAX];
        Scanner scan = new Scanner(System.in);
        for (int i = 0; i < NUM; i++) { //读取输入数据并按系数存入数组中
            int n = scan.nextInt();
            for (int j = 0; j < n; j++) {
                int exp = scan.nextInt();
                float conf = scan.nextFloat();
                poly[exp] += conf;
            }
        }
        int count = 0;
        int[] out = new int[MAX];
        for (int i = 0; i < MAX; i++) { //统计个数
            if (poly[i] != 0.0) {
                out[count] = i;
                count++;
            }
        }
        System.out.print(count);
        for(int i = count - 1; i >= 0; i--) { //格式化打印
            System.out.printf(" %d %.1f", out[i], poly[out[i]]);
        }
    }
}

 Note: 我写的这个Java版本只是部分正确，找了很多遍，没有找出bug，恳请大神指点！

Python Version One:

def solution1():
    if __name__ == "__main__":
        '''读取两行多项式分割成list'''
        a = input().split()
        b = input().split()
        m = {}

        k1 = eval(a[0])
        k2 = eval(b[0])

        '''将第一行元素按系数存入字典中'''
        i = 0
        while i < k1:
            m[a[2*i+1]] = eval(a[2*i+2])
            i += 1

        '''将第二行元素按系数存入字典中'''
        j = 0
        while j < k2:
            if b[2*j+1] in m.keys():
                m[b[2*j+1]] += eval(b[2*j+2])
            else:
                m[b[2 * j + 1]] = eval(b[2 * j + 2])
            j += 1
        '''统计字典中值为非0的个数'''
        count = 0
        for k, v in m.items():
            if v != 0:
                count += 1

        '''格式化打印'''
        if count:
            print(count, end=" ")
        else:
            print(count, end="")
        output = ""
        if count != 0:
            for (k, v) in sorted(m.items(), key=lambda x: x[0], reverse=True):
                if v != 0:
                    output += k + " " + str(round(v, 1)) + " "
            print(output.rstrip(), end='')

 Note: 提交的时候不要用函数！

Python Version Two:

def solution2():
    output = [0 for i in range(1001)]
    a = input().split(" ")
    b = input().split(" ")
    for i in range(int(a[0])):
        output[int(a[i * 2 + 1])] += float(a[i * 2 + 2])
    for i in range(int(b[0])):
        output[int(b[i * 2 + 1])] += float(b[i * 2 + 2])
    count = 0
    for i in range(1001):
        if output[i]:
            count += 1
    if count:
        print(count, end=" ")
    else:
        print(count)
    for i in range(1000, -1, -1):
        if output[i]:
            count -= 1
            if count > 0:
                print(i, round(output[i], 1), end=" ")
            else:
                print(i, round(output[i], 1))

Note: 提交的时候不要用函数！

4.Summay

1. 如果相加后值为0，不进行输出
2. size等于0直接输入0（无空格）
3. 输出时只能有一个空格 

 水滴石穿，笨鸟先飞！：D