Problem Description
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.
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.
Input
Each line will contain one integer n(0 < n < 1000000).
Output
Output the LPF(n).
Sample Input
1 2 3 4 5
Sample Output
0 1 2 1 3
Author
Wiskey
Source
Recommend
威士忌
思路：题意是输入一个数，输出它的最大因子是第几位素数，可以采取打表的方法，对第一个素数以及第一个素数的倍数都输出1，第二个素数及其倍数都输出2，以此类推。
#include<stdio.h>
#include<cstring>
#include<algorithm>
#include<math.h>
#include<iostream>
using namespace std;
int a[1000000];
int main()
{
int i,j,k=0,n;
memset(a,0,sizeof(a));
for(i=2;i<1000000;i++)
{
if(a[i]==0)
{
k++;
for(j=i;j<1000000;j=j+i)
a[j]=k;
}
}
while(scanf("%d",&n)!=EOF)
{
printf("%d\n",a[n]);
}
return 0;
}