hdu-1877（大数+进制转换）

题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=1877

思路：注意考虑0,0的情况。

#include<iostream>
#include<cstdio>
#include<string>
#include<algorithm>
using namespace std;
int m,a,b;
string s1,s2;
string add(string s1,string s2)
{if(s1.length()<s2.length()) {string tp=s1;s1=s2;s2=tp;}int i,j,l1=s1.length(),l2=s2.length();for(i=l1-1,j=l2-1;i>=0;i--,j--){s1[i]=(char)(s1[i]+(j>=0?s2[j]-'0':0));if(s1[i]-'0'>=m){s1[i]=(char)((s1[i]-'0')%m+'0');if(i) s1[i-1]++;else s1="1"+s1;}}return s1;
}
string f(int x)
{string s2="";int i,j,tp;while(x){tp=x%m;x/=m;s2+=(char)(tp+'0');}reverse(s2.begin(),s2.end());//cout<<s2<<endl;return s2;
}
int main(void)
{while(cin>>m&&m){cin>>a>>b;if(a+b==0){cout<<0<<endl;continue;}s1=f(a);s2=f(b);cout<<add(s1,s2)<<endl;}return 0;
}