C++-蓝桥杯-小计算器[进制转化][模拟]

 #include <cstdio>
 #include <string>
 #include <cstring>
 #include <iostream>
 using namespace std;
 typedef long long ll;
 ll num,k=,ans;int t,calc,len;string str;char s[];
 ll get10(){
     ans=,scanf("%s",s+),len=strlen(s+);
     for(int i=;i<=len;i++)ans=ans*k+(s[i]>''?s[i]-'A'+:s[i]-'');
     return ans;
 }
 void print(ll x){if(x)print(x/k),putchar(x%k<=?x%k+'':x%k+'A'-);}
 void print(){if(num==)putchar('');else print(num);}//之前没考虑到答案为0
 void oper(){
     cin>>str;
     if(str=="CHANGE"){scanf("%lld",&k);return;}
     if(str=="EQUAL"){print(),puts("");return;}
     if(str=="CLEAR"){num=calc=;return;}
     if(str=="ADD"){calc=;return;}
     if(str=="SUB"){calc=;return;}
     if(str=="MUL"){calc=;return;}
     if(str=="DIV"){calc=;return;}
     if(str=="MOD"){calc=;return;}
     if(str=="NUM")
         switch(calc){
             case :num+=get10();break;//这里意思是刚刚CLEAR过
             case :num+=get10();break;
             case :num-=get10();break;
             case :num*=get10();break;
             case :num/=get10();break;
             case :num%=get10();break;
         }
 }
 int main(){
     for(scanf("%d",&t);t--;)oper();
     return ;
 }