PAT Grade A Brush Test Record-1001 A + B Format (20 points)

Calculate a+b and output the sum in standard format – that is, the digits must be separated into groups of three by commas (unless there are less than four digits).

Input Specification:

Each input file contains one test case. Each case contains a pair of integers a and b where −10^​6≤a,b≤10^​6. The numbers are separated by a space.

Output Specification:

For each test case, you should output the sum of a and b in one line. The sum must be written in the standard format.

Sample Input:

-1000000 9

Sample Output:

-999,991

Ideas

This question is very simple to do with a string type. Simply insert the read string from the last third digit into the comma "," (here the loop end condition must be written i> 0, not i> = 0, Otherwise, when the result is exactly six digits, the first digit will also be a comma (such as the case given in the example)), but here must be divided into positive and negative cases, if it is a negative number, first take the negative sign Come out, and then operate normally according to the previous positive method, and finally insert the negative sign back ~

Code

#include<cstdio> 
#include<string>
#include<iostream>
using namespace std;
int main(){
	int tmp1, tmp2;
	cin>>tmp1>>tmp2;
	int sum = tmp1+tmp2;
	string result = to_string(sum);
	if(result[0]=='-'){
		string temp = result.substr(1,result.length()-1);
		for(int i=temp.length()-3;i>0;i-=3) temp.insert(i,",");
		result = temp;
		result.insert(0,"-");
	}
	else{
		for(int i=result.length()-3;i>0;i-=3) result.insert(i,",");
	}
	cout<<result;
    return 0;
}