[原创]LightOJ 1035 Intelligent Factorial Factorization [预处理+一半的 质因子分解]【数论】

# include <stdio.h>
# include <stdlib.h>
# include <string.h>
# include <limits.h>
# include <malloc.h>
# include <ctype.h>
# include <math.h>
# include <string>
# include <iostream>
# include <algorithm>
# include <map>
# include <vector>
# include <set>

using namespace std;

# define LL unsigned long long int

int Is_or[500];
void Prime()
{
    int n=200;
    int k=0;
    memset(Is_or,1,sizeof(Is_or));
    Is_or[0]=Is_or[1]=0;
    for(int i=2; i<n; i++)
    {
        if(Is_or[i])
        {
            for(int j=i+i; j<n; j+=i)
            {
                Is_or[j]=0;
            }
        }
    }
    return ;
}

int has[105][105];

void init()
{
    int num;
    memset(has,0,sizeof(has));
    for(int i=2;i<=100;i++)
    {
        for(int j=2;j<=i;j++)
        {
            num=i;
            if(num%j==0&&Is_or[j])
                while(num%j==0)
                    has[i][j]++,num/=j;
        }
    }

    for(int i=1;i<=100;i++)
    {
        for(int j=1;j<=100;j++)
        {
            has[i][j]+=has[i-1][j];
        }
    }

    return ;
}

int main()
{
    Prime();
    init();
    int t,tt=0,num;
    LL p,l;
    scanf("%d",&t);
    while(t--)
    {
        int n,m;
        scanf("%d",&n);
        printf("Case %d: %d = ",++tt,n);

        printf("%d (%d)",2,has[n][2]);
        for(int i=3;i<=n;i++)
        {
            if(has[n][i])
            printf(" * %d (%d)",i,has[n][i]);
        }
        printf("\n");
    }
    return 0;
}