浮点数的大数加法

// PTest.cpp : Defines the entry point for the console application.//#include "stdafx.h"#include <iostream>#include <fstream>#include <cmath>#include <string>#include <iomanip>#include <algorithm>#include <stdio.h>//using namespace std;std::ifstream cin("in.txt");std::ofstream cout("out.txt");std::string big_plus(std::string a,std::string b,int& op,bool point_flag){std::string reusult = "";if ( a.length()<b.length()){std::swap( a,b);}if (point_flag){//小数部分的加法在后面补零for (int i =a.length()-b.length();i>0;i--){b = b+"0";}} else{//整数部分的加法，在前面补零for (int i =a.length()-b.length();i>0;i--){b = "0"+b;}}int i,j,t;for (i = a.length()-1;i>=0;i--){t = a[i]-'0'+b[i]-'0'+op;reusult += '0'+t%10;op = t/10;}std::reverse(reusult.begin(),reusult.end());return reusult;}std::string big_point_plus(std::string a,std::string b){std::string a_point_part;std::string b_point_part;std::string result_point_part;std::string result_int_part;std::string a_int_part;std::string b_int_part;int a_p = std::find(a.begin(),a.end(),'.')-a.begin();int b_p = std::find(b.begin(),b.end(),'.')-b.begin();a_int_part = a.substr(0,a_p);a_point_part = a.substr(a_p+1,a.length());b_int_part = b.substr(0,b_p);b_point_part = b.substr(b_p+1,b.length());int op = 0;//小数部分相加result_point_part = big_plus(a_point_part,b_point_part,op,true);//整数部分的加法result_int_part = big_plus(a_int_part,b_int_part,op,false);return result_int_part+"."+result_point_part;}int main(int argc, char* argv[]){std::string a,b;while (cin>>a>>b){cout<<big_point_plus(a,b)<<std::endl;}return 0;}