题解 | 浮点数加法

//与进位相关的思路，复习的时候要注意
#include<iostream>
#include<algorithm>
#include<vector>
#include<string>
#include<set>
#include<cmath>
using namespace std;

int main()
{
    string s1,s2;
    getline(cin,s1);
    getline(cin,s2);
    int i1 = s1.find('.');
    int i2 = s2.find('.');
    string zs1 = s1.substr(0,i1);
    string zs2 = s2.substr(0,i2);
    string xs1 = s1.substr(i1+1);
    string xs2 = s2.substr(i2+1);
    string xs3;
    string zs3;

    int len_xs1=xs1.size();
    int len_xs2=xs2.size();
    int len_zs1=zs1.size();
    int len_zs2=zs2.size();

    if(len_xs1>len_xs2)
    {
      xs3 = xs1;
    }
    else{
        xs3 = xs2;
    }
    if(len_zs1>len_zs2)
    {
      zs3 = zs1;
    }
    else{
        zs3 = zs2;
    }

    int min_xs = min(len_xs1,len_xs2);
    int min_zs = min(len_zs1,len_zs2);
    int max_xs = max(len_xs1,len_xs2);
    int max_zs = max(len_zs1,len_zs2);
    
    int flag=0;
    for(int i=min_xs-1;i>=0;i--)
    {
        int sum=0;
        sum = sum+(xs1[i]-'0')+(xs2[i]-'0')+flag;

        if(sum>=10)
        {
            flag=1;
            xs3[i]=(sum%10)+'0';
        }
        else{
            flag=0;
            xs3[i]=sum+'0';
        }
    }
    

    int chazhi = max_zs-min_zs;
    int flag2=0;
    for(int j=max_zs-1;j>=0;j--)
    {
        int sum2=0;
        if(len_zs1>len_zs2)
        {
            if(j-chazhi>=0)
            {
                sum2 += sum2+(zs1[j]-'0')+(zs2[j-chazhi]-'0')+flag+flag2;
            }
            else{
                sum2 += sum2+(zs1[j]-'0')+0+flag+flag2;
            }
        }
        else{
            if(j-chazhi>=0)
            {
                sum2 += sum2+(zs2[j]-'0')+(zs1[j-chazhi]-'0')+flag+flag2;
            }
            else{
                sum2 += sum2+(zs2[j]-'0')+0+flag+flag2;
            }
        }

        if(flag==1) 
        {
            flag=0;
        }

        if(sum2>=10)
        {
            flag2=1;
            if(j!=0)
            {
                zs3[j] = (sum2%10)+'0';
            }
            else{
                zs3[j] = (sum2%10)+'0';
                zs3.insert(0,(sum2/10)+"0");
            }
        }
        else{
            flag2=0;
            zs3[j] = sum2+'0';
        }
    }
cout<<zs3<<'.'<<xs3<<endl;
return 0;

}