shunfurh
编程介的小学生
采纳率100%
2017-06-06 12:01

Largest prime factor

  • each
已采纳

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.

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

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2条回答

  • coder_lj 凝视深空 4年前
     #include<iostream>
    #include<cmath>
    using namespace std;
    
    bool isPrime(int n)
    {
        for (int i = 2; i <= sqrt(n); ++i)
        {
            if (n % i == 0)
                return false;
        }
        return true;
    }
    
    int main()
    {
        int num;
        while(cin >> num)
        {
            if (isPrime(num))
            {
                int pos = 0;
                if (num > 1)
                    pos = 1;
                for (int i = 3; i <= num; i += 2)
                {
                    if (isPrime(i))
                        pos++;
                }
                cout << "position is:" << pos << endl;
            }
            else
                cout << "position is:" << 1 <<endl;
        }
        return 0;
    }
    
    

    图片说明

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  • coder_lj 凝视深空 4年前

    不是素数的就默认position为1

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