hdu 4432 Sum of divisors（模拟）

#include <iostream>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <vector>
using namespace std;
#define LL long long
vector <int> Div;
char c[10000];
void solve(LL n){
    int k=sqrt(n);
    for(int i=1;i<=k;i++){
		if(n%i==0){
			Div.push_back(i);
			if(i!=(n/i)) Div.push_back(n/i);
		}
    }
}

LL Get(LL n,int m){
	LL res=0;
    while(n>0){
		int tmp=n%m;
		LL T=tmp*tmp;
		res+=T;
		n/=m;
    }
    return res;
}

int change(LL n,int m){
    LL res=0;
	int i=0;
    while(n>0){
		LL tmp=n%m;
		char tc;
		if(tmp==10) tc='A';
		else if(tmp==11) tc='B';
		else if(tmp==12) tc='C';
		else if(tmp==13) tc='D';
		else if(tmp==14) tc='E';
		else if(tmp==15) tc='F';
		else tc=char(tmp+'0');
		c[i]=tc;
		n/=m;
		i++;
    }
    i--;
    return i;
}
int main(){
	int m;
	LL n;
	while(~scanf("%I64d%d",&n,&m)){
		Div.clear();
		solve(n);
		LL res=0;
		for(int i=0;i<Div.size();i++){
			res+=Get(Div[i],m);
		}
		int len=change(res,m);
		for(int i=len;i>=0;i--){
			printf("%c",c[i]);
		}
		printf("\n");
		
	}
	return 0;
}