16进制转为8进制

//十六进制转8进制
#include<iostream>

using namespace std;

int main(void)
{
 int n;
 scanf("%d",&n);
 while(n--)
 {
  string s1,s2;
  cin>>s1;
  for(int i=0;i<s1.length();i++)
  {
   switch(s1[i])
   {
    case ‘0‘:s2+="0000";break;
    case ‘1‘:s2+="0001";break;
    case ‘2‘:s2+="0010";break;
    case ‘3‘:s2+="0011";break;
    case ‘4‘:s2+="0100";break;
    case ‘5‘:s2+="0101";break;
    case ‘6‘:s2+="0110";break;
    case ‘7‘:s2+="0111";break;
    case ‘8‘:s2+="1000";break;
    case ‘9‘:s2+="1001";break;
    case ‘A‘:s2+="1010";break;
    case ‘B‘:s2+="1011";break;
    case ‘C‘:s2+="1100";break;
    case ‘D‘:s2+="1101";break;
    case ‘E‘:s2+="1110";break;
    case ‘F‘:s2+="1111";break;
    default:break;
   }
  }
  
  if(s2.length()%3==1)
      s2="00"+s2;
  else if(s2.length()%3==2)
      s2="0"+s2;
  int flag=0;
  for(int i=0;i<s2.length();i+=3)
  {
   int m=(s2[i]-‘0‘)*4+(s2[i+1]-‘0‘)*2+(s2[i+2]-‘0‘)*1;
   
   if(m!=0||flag!=0)
       printf("%d",m);
   flag++;
   }
  printf("\n");
  }
  return 0;
}

原文地址：https://www.cnblogs.com/cxwpluto/p/12432520.html