hdu 2031 damn进制!

#include<iostream>#include<string>using namespace std;int pow(int x,int y){  //求x的y次方int i,s=1;if(y==0){return 1;}for(i=0;i<y;i++){s*=x;}return s;}int main(){int t=1;int n,r;string ans;while(cin>>n>>r){int i=0;ans="";if(n<0){t=0;n=-n;}while(n>pow(r,i)){//i++;}i=i-1;int s;while(i>=0){s=n/pow(r,i);n=n%pow(r,i);if(s>=10){if(s==10)ans+='A';if(s==11)ans+='B';if(s==12)ans+='C';if(s==13)ans+='D';if(s==14)ans+='E';if(s==15)ans+='F';}elseans+=('0'+s);i--;}if(t==0)cout<<"-"<<ans<<endl;elsecout<<ans<<endl;t=1;}return 0;}