PAT甲级1001

传送门

#include <iostream>#include <string>#include <vector>using namespace std;int main(int argc,char **argv){int n,m,sum;vector<char> ivec;scanf("%d%d",&n,&m);sum=n+m;string src=std::to_string(sum);if(sum<0){int len=src.length()-1;if(len<=3){cout<<src;return 0;}int commas_num;if(len>3 && len%3==0)commas_num=len/3-1;elsecommas_num=len/3;for(int j=len,k=0;j>=0;j--){ivec.push_back(static_cast<char>(src[j]));if(++k%3==0 && commas_num>0){ivec.push_back(',');commas_num--;}}for(auto it=ivec.rbegin();it!=ivec.rend();it++)cout<<*it;}if(sum>=0){int len=src.length();if(len<=3){cout<<src;return 0;}int commas_num;if(len>3 && len%3==0)commas_num=len/3-1;elsecommas_num=len/3;for(int j=len-1,k=0;j>=0;j--){ivec.push_back(static_cast<char>(src[j]));if(++k%3==0 && commas_num>0){ivec.push_back(',');commas_num--;}}for(auto it=ivec.rbegin();it!=ivec.rend();it++)cout<<*it;}return 0;}