abc142_d(互质共因子个数)

寻找a和b的互质公因子:

a和b的公因子小于等于gcd(a,b)

然后互质等价于筛gcd内的质数(公因子是gcd的因数)

复杂度O(sqrt(n))

#include<bits/stdc++.h>
#define int long long 
#define pb push_back
#define fi first
#define se second 
#define bg begin()
#define ed end()
#define rbg rbegin()
#define all(x) x.bg,x.ed
using namespace std;
const long long inf=2e18;
typedef long long ll;
typedef pair<ll,ll>pii;
typedef vector<ll>vi;
const double eps=1e-8;
const long double pi=acos(-1.0);
const int mod=998244353;
const int N=2e5+5;
void solve(){
    int a,b;
    cin>>a>>b;
    int tmp=__gcd(a,b);
    int ans=0;
    for(int i=2;i<=tmp/i;i++){
        if(tmp%i==0){
            ans++;
            while(tmp%i==0)tmp/=i;
        }
    }
    if(tmp>1)ans++;
    cout<<ans+1<<endl;
}        
signed main(){
    #ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
    #endif 
    ios::sync_with_stdio(false);
      cin.tie(0);
    //int t;
    //cin>>t;
    //while(t--){
        solve();
    //}
    return 0;
}        

 

posted @ 2022-10-16 00:30  Candyk8d9  阅读(56)  评论(0)    收藏  举报