Nine degrees OJ 1207 mass factor number (sieve prime, barely AC)

1 seconds

Memory limit:32 MB

Special question: No

submitted:4466

Resolution:1375

Title Description:

The

number of the mass factor for a positive integer N (n>1). The same quality factor requires repeated calculations. such as 120=2*2*2*3*5, a total of 5 qualitative factors.

Input:

There may be multiple sets of test data, and the input to each set of test data is a positive integer N, (1<n<10^9).

Output:

For each set of data, the number of the quality factor of the output n.

Sample input:

120

Sample output:

5

Tips:

Note: 1 is not a mass factor of N; n is the mass factor of N if n is a prime number.

Source:

2007, Tsinghua University computer Research Life Test real problem

If all the factors in the test 2 to 100000 are not decomposed to 1, a also has a factor greater than 100000 ans++; Solution 1:

#include <stdio.h> #define M 100000int prime[m];int flag[m];int cnt;void getprime () {    cnt=1;    for (int i=2;i<m;++i)    {        if (!flag[i])        {            prime[cnt++]=i;            for (int j=i;j<m;j+=i)                flag[j]=1;}}    } int main (int argc, char *argv[]) {    //freopen ("1207.in", "R", stdin);    int num;    Getprime ();    while (scanf ("%d", &num)!=eof)    {        int ans=0;        int i;        for (I=1;i<cnt;++i) {            while (num%prime[i]==0) {                ans++;                Num/=prime[i];            }            if (num==1) break;        }        if (i==cnt)           ans++;        printf ("%d\n", ans);    }    return 0;}

Solution 2:

#include <iostream> #include <stdio.h>using namespace std;int main (int argc, char *argv[]) {    int num;    Freopen ("1207.in", "R", stdin);    while (scanf ("%d", &num)!=eof)    {        int ans=0;        int i=2;        int n=num;        while (i*i<=n) {            if (num%i==0)            {                num/=i;                ans++;            }            else                i++;        }        if (num!=1)            ans++;        printf ("%d\n", ans);    }    return 0;}

Time Comparison--

Solution One:

Solution Two:

I don't see the difference.

Nine degrees OJ 1207 mass factor number (sieve prime, barely AC)