Aladdin and the Flying Carpet LightOJ - 1341 唯一分解/数论/合数分解模板

//#pragma comment(linker, "/STACK:1024000000,1024000000")
#include<bits/stdc++.h>
#include<stdio.h>
#include<algorithm>
#include<queue>
#include<string.h>
#include<iostream>
#include<math.h>
#include<set>
#include<map>
#include<vector>
#include<iomanip>
using namespace std;
#define ll long long
#define pb push_back
#define FOR(a) for(int i=1;i<=a;i++)
const double PI = acos(-1.0);

const int maxn=1e6+7;
const int mod=998244353;

int prime[maxn+1];
void getprime(){
memset(prime,0,sizeof prime);
for(int i=2;i<=maxn;i++){
if(!prime[i])prime[++prime[0]]=i;
for(int j=1;j<=prime[0] && prime[j]<=maxn/i;j++){
prime[prime[j]*i]=1;
if(i%prime[j]==0)break;
}
}
}

ll factor[100][2];
int fatcnt;
int getFactors(ll x){
fatcnt=0;
ll tmp=x;
int ret=1;

for(int i=1;prime[i]<=tmp/prime[i];i++){
factor[fatcnt][1]=0;
if(tmp%prime[i]==0){
factor[fatcnt][0]=prime[i];
while(tmp%prime[i]==0){
factor[fatcnt][1]++;
tmp/=prime[i];
}
//fatcnt++;
ret*=(factor[fatcnt][1]+1);
}
}
if(tmp!=1){
//factor[fatcnt][0]=tmp;
//factor[fatcnt++][1]=1;
ret*=2;
}
ret/=2;//毯子算同一种
//return fatcnt
return ret;
}

void solve(ll a,ll b,int t){
if(a/b<b){
printf("Case %d: 0\n",t);return;
}
int ans=getFactors(a);

for(ll i=1;i<b;i++){
if(a%i==0)ans--;
}
printf("Case %d: %d\n",t,ans);
}

int main(){
int T;scanf("%d",&T);
int t=0;
getprime();
while(t!=T){
t++;
ll a,b;
scanf("%lld%lld",&a,&b);
solve(a,b,t);
}
}