uva10780

将m分解质因数，然后计算次数取最小。

#include <iostream>
#include <cstdio>
#include <cmath>
#include <algorithm>
#include <vector>
#include <iomanip>
#include <cstring>
#include <map>
#include <queue>
#include <set>
#include <cassert>
#include <stack>
#include <bitset>
#define mkp make_pair
using namespace std;
const double EPS=1e-8;
typedef long long lon;
const lon SZ=5007,INF=0x7FFFFFFF,mod=10000007;
int n,m,res;
bool isp[SZ];
vector<int> pri;

void init()
{
    res=0;
    cin>>n>>m;
}


void work(int x,int y)
{
    if(y==0)return;
    res+=y/x;
    work(x,y/x);
}

int main()
{    
    memset(isp,1,sizeof(isp));
    for(int i=2;i<SZ;++i)
    {
        if(isp[i])
        {
            pri.push_back(i);
            for(int j=i*i;j<SZ;j+=i)
            {
                isp[j]=0;
            }
        }
    }
    std::ios::sync_with_stdio(0);
    //freopen("d:\\1.txt","r",stdin);
    lon casenum;
    cin>>casenum;
    //cout<<casenum<<endl;
    for(lon time=1;time<=casenum;++time)
    //for(lon time=1;cin>>n>>m,n;++time)
    {
        init();
        map<int,int> mp;
        int tmp=n;
        for(int i=0;i<pri.size();++i)
        {
            for(;tmp%pri[i]==0;)
            {
                ++mp[pri[i]];
                tmp/=pri[i];
            }
        }
        int minv=INF;
        for(auto it=mp.begin();it!=mp.end();++it)
        {
            res=0;
            work(it->first,m);
            int cur=res/it->second;
            minv=min(minv,cur);
        }
        cout<<"Case "<<time<<":"<<endl;
        if(minv)cout<<minv<<endl;
        else cout<<"Impossible to divide"<<endl;
    }
    return 0;
}