hdu2136 ----Largest prime factor

Largest prime factor

Time Limit: 5000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)

Total Submission(s): 13740    Accepted Submission(s): 4852

[align=left]Problem Description[/align]
Everybody knows any number can be combined by the prime number.

Now, your task is telling me what position of the largest prime factor.

The position of prime 2 is 1, prime 3 is 2, and prime 5 is 3, etc.

Specially, LPF(1) = 0.

 

[align=left]Input[/align]
Each line will contain one integer n(0 < n < 1000000).

 

[align=left]Output[/align]
Output the LPF(n).

 

[align=left]Sample Input[/align]

1
2
3
4
5

 

[align=left]Sample Output[/align]

0
1
2
1
3

 
模板题

#include<iostream>
#include<cmath>
#include<cstring>
#include<vector>
#include<stdlib.h>
#include<stdio.h>
#include<algorithm>
#include<map>
#include <set>
#include <list>
#include <deque>
#include<sstream>
#include<time.h>
#define pi 3.1415926
using namespace std;

typedef long long ll;
const int maxn = 1000000 + 5;
const int day =21252;
const int mod=1000000007;
const ll N=1000000;
ll prime
={0},num_prime=0;
ll isnotprime
={1,1};

void kuai()
{
memset(prime,0,sizeof(prime));
ll t=1;
for(int i=2;i<N;i++)
{
if(!prime[i])
{
for(int j=i;j<N;j+=i)
{
prime[j]=t;
}
t++;
}
}
}
int main()
{
ll n;
kuai();
while(~scanf("%lld",&n))
{
if(n==1)
cout<<"0"<<endl;
else
cout<<prime
<<endl;
}
return 0;
}