UVA 10780

题目链接

思路好想，注意细节。错了很多次。

#include <cstdio>
#include <cstring>
#include <string>
#include <cmath>
#include <ctime>
#include <cstdlib>
#include <iostream>
using namespace std;
#define MOD 1000000
int prim[5001];
int o[5001];
int flag[5001];
int aim[5001];
int main()
{
    int t,n,m,i,j,num = 0,minz,temp,cas = 1;
    for(i = 2;i <= 5000;i ++)
    {
        if(!o[i])
        {
            prim[num++] = i;
            for(j = i+i;j <= 5000;j += i)
            {
                o[j] = 1;
            }
        }
    }
    scanf("%d",&t);
    while(t--)
    {
        scanf("%d%d",&m,&n);
        int tm = m;
        memset(flag,0,sizeof(flag));
        memset(aim,0,sizeof(aim));
        for(i = 2;i <= n;i ++)
        {
            temp = i;
            for(j = 0;j < num;j ++)
            {
                if(temp == 1) break;
                while(temp%prim[j] == 0)
                {
                    flag[j] ++;
                    temp /= prim[j];
                }
            }
        }
        minz = 1000000;
        for(j = 0;j < num;j ++)
        {
            while(m%prim[j] == 0)
            {
               aim[j] ++;
               m /= prim[j];
            }
        }
        for(j = 0;j < num;j ++)
        {
            if(tm%prim[j] == 0)
            minz = min(flag[j]/aim[j],minz);
        }
        if(minz == 0)
        printf("Case %d:
Impossible to divide
",cas++);
        else
        printf("Case %d:
%d
",cas++,minz);
    }
    return 0;
}