A+B Format (20)

import java.util.Scanner;
//没什么难点，从第一位开始输出字符。
//count计数，每输出了三个字符（且不为最后一个字符）就输出一个“，”
public class Main {

	public static void main(String[] args) {
		Scanner in=new Scanner(System.in);
		long a=in.nextLong();
		long b=in.nextLong();
		long c=a+b;
		
		if(c<0){
			System.out.print("-");
			c=0-c;
		}
		
		String s=String.valueOf(c);
		String out="";
		int count=0;
		for(int i=s.length()-1;i>=0;i--){
			out=s.charAt(i)+out;
			count++;
			if(count%3==0&&i!=0){
				count=0;
				out=","+out;
			}
			
		}System.out.println(out);
	}

}

package go.jacob.day822;

import java.util.Scanner;

/**
 * 1001. A+B Format (20)
 * 
 * @author Jacob
 * 思路：从后往前遍历，每个三位加","。同时要考虑前一位是否为"-"和总位数是否小于4
 */
public class Demo2 {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int a = sc.nextInt(), b = sc.nextInt();
		String sum = a + b + "";
		int index = sum.length() - 3;
		StringBuilder res = new StringBuilder();
		while (index > 0) {
			if (sum.charAt(index - 1) != '-') {
				res.insert(0, "," + sum.substring(index, index + 3));

			} else
				break;
			index -= 3;
		}
		res.insert(0, sum.substring(0, index + 3));
		System.out.println(res);
		sc.close();
	}
}

// 差点忘了判断边界，
//而且第一次代码错了，竟然也过了(/ w\)
//蓝后用栈再做了一下～～^_-
#include <iostream>
#include <string>
#include <set>
#include <algorithm>
#include <iomanip>
#include <cstdio>
#include <vector>
#include <stdlib.h>
#include <stack>
#include <deque>
#include <cstring>
using namespace std;
#define Mod 1000000007

void  slove(int x);
int main()
{
    int a, b, ans;
    cin>>a>>b;
    ans=a+b;
    slove(ans);
    return 0;
}
void slove(int x){
    if(x==0) {cout<<"0"<<endl;return ;}
    if(x<0){cout<<"-"; x=-x;}
    stack<int>s;
    while(x){
        int t=x%10;
        s.push(t);
        x/=10;
    }
    while(!s.empty()){
        cout<<s.top();
        s.pop();
        int len=s.size();
        if(len%3==0&&len) cout<<",";
    }
    cout<<endl;
}  

#include<stdio.h>
int main()
{
	int x, y;
	while (~scanf("%d%d", &x, &y))
	{
		int sum = x + y;
		if (sum < 0)
		{
			printf("-");
			sum = -sum;
		}
		if (sum<1000 && sum>-1000)
			printf("%d\n", sum);
		else if (sum<1000000 && sum>-1000000)
			printf("%d,%03d\n", sum / 1000, sum % 1000);
		else
			printf("%d,%03d,%03d\n", sum / 1000000, sum / 1000 - 1000 * (sum / 1000000), sum % 1000);
	}
	return 0;
}

import java.util.*;
import java.io.*;

public class Main {
    public static void main(String[] args) {
        try(BufferedReader br = new BufferedReader(new InputStreamReader(System.in))){
            String[] input = br.readLine().split(" ");
            int sum = Integer.parseInt(input[0]) + Integer.parseInt(input[1]);
            if (Math.abs(sum) < 1000) {
                System.out.println(sum);
            } else {
                if (sum < 0) {
                    System.out.print('-');
                }
                sum = Math.abs(sum);
                ArrayList<Integer> list = new ArrayList<>();
                while (sum > 0) {
                    list.add(sum % 1000);
                    sum /= 1000;
                }
                int groups = list.size();
                System.out.print(list.get(groups - 1));
                for (int i = groups - 2; i >= 0; --i) {
                    System.out.print(",");
                    String num = String.valueOf(list.get(i));
                    for (int j = 0; j <    3 - num.length(); ++j) {
                        System.out.print(0);
                    }
                    System.out.print(num);
                }
                System.out.println();
            }
        } catch (IOException ie){}
    }
}

#include<bits/stdc++.h>
using namespace std;

int main() {
	int a,b;
	cin>>a>>b;
	int c=a+b;
	if(c<0) cout<<'-';
	string s=to_string(abs(c)),answer;
	reverse(s.begin(),s.end());
	for(int i=s.size()-1; i>=0; i--) {
		cout<<s[i];
		if(i>0&&i%3==0) cout<<',';
	}
	return 0;
}

#include<iostream>
using namespace std;
int main(){
    int a,b,sum;
    int num[10];   //倒序存储和的绝对值的数组
    cin>>a>>b;
    sum=a+b;
    if(sum<0){
        cout<<"-";
        sum=-sum;
    }
    int i;
    for(i=0;sum>0;i++){
        num[i]=sum%10;
        sum/=10;
    }
    for(int j=i-1;j>=0;j--){
        cout<<num[j];
        if(j%3==0&&j!=0)
            cout<<",";
    }
    return 0;
}

#include <iostream>
#include <bits/stdc++.h>
using namespace std;
int main() {
    int a,b,c;
    cin >> a >> b;
    c=a+b;
    if(c>=-999 && c<=999) cout << c;
    else{
        if(c<0) cout << "-";
        c=max(c,-c);
        vector<char> ans;
        int flag=0;
        while(c){
            int tmp=c%10;
            if(flag==3){
                flag=0;
                ans.push_back(',');
            }
            ans.push_back(tmp+'0');
            flag++;
            c=c/10;
        }
        for(int i=ans.size()-1;i>=0;i--)
            cout << ans[i];
    }

    return 0;
}

print("{:,}".format(sum(map(int,input().split()))))

#include<iostream>
#include<vector>
#include<string.h>
#include<map>
#include <string>
using namespace std;
void aplusbformat() {
	long long a, b;
	vector<long long>q;
	cin >> a >> b;
	a += b;
	if (a < 0) {
		cout << "-";
		a = -a;
	}
	else if (a == 0) {
		cout << "0";
	}
	 while (a != 0) {
		q.push_back(a%10);//
		a /= 10;
	}
	vector<string> qp;
	auto it = q.begin();
	int i1 = 0;
	while (it != q.end()) {
		if (i1 != 0&&i1 % 3 == 0) {
			qp.push_back(",");
		}
		i1++;
		string s = to_string(*it);
		qp.push_back(s);
		it++;
	}
	while (qp.size() != 0) {
		cout << qp.back();
		qp.erase(qp.end()-1);
	}
}
//-1000000 9
int main()
{
	aplusbformat();
	return 0;
}

#include <iostream>

#include <string>

using namespace std;

int main() {

//第一种方法

    int a, b, c;

    string s;

    cin>>a>>b;

    c = a + b;

    s = to_string(c);// to_string 将数值转化为字符串。返回对应的字符串。

    int n = s.size();

    int temp = 0;

    if (c < 0) temp = 1;

    for (int i = n - 3; i > temp; i -= 3) {

        s.insert(i, ",");// s.insert(pos, str)，pos是待插入的位置， str是待插入的字符串

    }

    cout << s << endl;

//第二种方法

    int k[8],i=0,flag=0;//建立数组，两个七位数相加最多八位数，所以选择k[8]

    if(c<0){

        c=-c;

        flag=1;

    }

    if(c==0)cout<<"0";

    else{

        while(c)

        {

            k[7-i]=c%10;

            c=c/10;

            i++;

        }

        if(flag)cout<<"-";

        for(i=8-i;i<8;i++)//8-i为该数组的起始位置

        {

            cout<<k[i];

            if(i==1||i==4)

                cout<<",";

        }

    }

    return 0;

}

	
	

		import java.util.Scanner;
	

	

		public class Main{
	

	

		static Scanner scanner = new Scanner(System.in);
	

	

		public static void main(String[] args) {
	

	

		int a = scanner.nextInt();
	

	

		int b = scanner.nextInt();
	

	

		String c = String.valueOf(a + b);
	

	

		StringBuilder s = new StringBuilder();
	

	

		int flag = 0;
	

	

		for (int i = c.length() - 1; i >= 0 ; i--) {
	

	

		s.append(c.charAt(i));
	

	

		flag++;
	

	

		if (flag % 3 == 0){
	

	

		s.append(',');
	

	

		}
	

	

		}
	

	

		String x = s.reverse().toString();
	

	

		x = x.replace("-,","-");
	

	

		if (x.startsWith(",")){
	

	

		x = x.substring(1);
	

	

		}
	

	

		System.out.println(x);
	

	

		}
	

	

		}
	

python两行搞定

a,b = map(int,input().split())
c = str(a + b)
lsc= []
for i in c:
    lsc.append(i)
cnt = 0
lsout = []
for i in range(len(lsc)-1,-1,-1):
    if lsc[i]>='0' and lsc[i]<='9':
       cnt+=1
if cnt>6:
   lsout = lsc[:len(lsc)-6]+[","]+lsc[len(lsc)-6:len(lsc)-3]+[',']+lsc[len(lsc)-3:]     
elif cnt>3:
    lsout = lsc[:len(lsc)-3]+[',']+lsc[len(lsc)-3:]   
out = ''
for i in lsout:
    out = out + i
if out!='':
    print(out)
else:
    for i in lsc:
        out = out + i
    print(out)

#include <iostream>
#include <vector>

using namespace std;

vector<int> divided_sum;

int main()
{     int a, b;     cin >> a >> b;     int sum = a + b;     if (sum < 0) {         cout << "-";         sum = -sum;     }     if (sum == 0) {         cout << "0";     } else {         int temp = 0;         while (sum != 0) {             temp = sum % 1000;             divided_sum.push_back(temp);             sum = sum / 1000;         }         for (int i = divided_sum.size() - 1; i >= 1; i--) {             cout << divided_sum[i] << ",";         }         cout << divided_sum[0];     }              system("pause");     return 0;
}

#include <iostream>
#include <vector>
#include <string>
#include <sstream>
/* run this program using the console pauser or add your own getch, system("pause") or input loop */
using namespace std;
// 思路：　题目的意思就是Ａ＋Ｂ　然后输出Ｃ，Ｃ有一定的格式，每大于３个数要输出一个“，”
// 个人的思路就是先给一个count 赋初值。如果这个初值为１　就是把纯数字的部分凑层３的倍数这样才能从大到小的添加“，”
// That's all,Thinks!
int main(int argc, char** argv) {
    long A;
    long B;
    cin >> A >> B;
    long C = A + B;
    stringstream ss;
    ss << C;
    string C2;
    ss >> C2;
    int count = 0;
    int i = 0;
    if(C<0){
        cout<< "-";
        i = 1;
    }
    count = 3 - (C2.size()-i) % 3;
    if(count == 3)
        count = 0;
    for(; i<C2.size(); i++)
    {
        count ++;
        cout << C2[i];
        if(count >= 3 && i != C2.size() - 1)
        {
            cout << "," ;
            count = 0;
        }
    }
    cout << endl;
    //while(1);
    return 0;
     
}

请注意了，由于测试用例有一些不同，在牛客网提交时不判断a+b的结果为0的情况时也可以通过测试用例，但在PAT中提交必须判断a+b等于0的情况，否则会有一个测试点不通过。