So easy(?)（不是最好的）

#include<iostream>
#include<string>
using namespace std;
int main(){
    int count;
    cin>>count;
    while(count--){
        int a;
        string b,c,e;
        char d;
        cin>>a>>b>>c>>d>>e;
        if(b=="km"&&e=="mm"){
            cout<<a<<" "<<"km"<<" "<<"="<<" "<<a*1000000<<" "<<"mm"<<endl;
        }
        else if(b=="km"&&e=="m"){
            cout<<a<<" "<<"km"<<" "<<"="<<" "<<a*1000<<" "<<"m"<<endl;
        }
        else if(b=="m"&&e=="mm"){
            cout<<a<<" "<<"m"<<" "<<"="<<" "<<a*1000<<" "<<"mm"<<endl;
        }
        else if(b=="kg"&&e=="g"){
            cout<<a<<" "<<"kg"<<" "<<"="<<" "<<a*1000<<" "<<"g"<<endl;
        }
        else if(b=="kg"&&e=="mg"){
            cout<<a<<" "<<"kg"<<" "<<"="<<" "<<a*1000000<<" "<<"mg"<<endl;
        }
        else if(b=="g"&&e=="mg"){
            cout<<a<<" "<<"g"<<" "<<"="<<" "<<a*1000<<" "<<"mg"<<endl;
        }
    }
    
}

有32行代码块