Codeforces #920F: SUM and REPLACE 题解

打一个表可以发现1e6以内的数都可以在6次求约数个数操作内变为2和1
所以更新操作不会很多
所以可以用树状数组来更新，并用并查集维护哪些格子还没有降到2和1#include <cstdio>
#include <iostream>
#include <cstring>
#include <string>
#include <cstdlib>
#include <utility>
#include <cctype>
#include <algorithm>
#include <bitset>
#include <set>
#include <map>
#include <vector>
#include <queue>
#include <deque>
#include <stack>
#include <cmath>
#define LL long long
#define LB long double
#define x first
#define y second
#define Pair pair<int,int>
#define pb push_back
#define pf push_front
#define mp make_pair
using namespace std;

const int MOD=1e9+7;
const LL LINF=2e16;
const int INF=2e9;
const int magic=348;
const double eps=1e-10;
const double pi=3.14159265;

inline int getint()
{
char ch;int res;bool f;
while (!isdigit(ch=getchar()) && ch!='-') {}
if (ch=='-') f=false,res=0; else f=true,res=ch-'0';
while (isdigit(ch=getchar())) res=res*10+ch-'0';
return f?res:-res;
}

int n,q;
int a[300048],d[1000048];

int prime[1000048],tot;bool isprime[1000048];
inline void sieve()
{
int i,j;
memset(isprime,true,sizeof(isprime));
for (i=2;i<=1000000;i++)
{
if (isprime[i]) prime[++tot]=i;
for (j=1;j<=tot && (long long)i*prime[j]<=1000000;j++)
{
isprime[i*prime[j]]=false;
if (i%prime[j]==0) break;
}
}
}

int go(int x)
{
int res=1,i,cnt;
for (i=1;i<=tot;i++)
{
if (x%prime[i]==0)
{
cnt=0;
while (x%prime[i]==0)
{
cnt++;
x/=prime[i];
}
res*=(cnt+1);
}
if (x==1 || prime[i]>int(sqrt(x))) break;
}
if (x!=1) res*=2;
return res;
}

namespace BIT
{
#define LOWBIT(x) x & (-x)
LL c[300048];
inline void update(int x,int delta) {while (x<=n) {c[x]+=delta;x+=LOWBIT(x);}}
inline LL query(int x){LL res=0;while (x) {res+=c[x];x-=LOWBIT(x);}return res;}
inline LL calc(int left,int right) {return query(right)-query(left-1);}
}

namespace DSU
{
int i,pre[300048],rnk[300048];
inline void init() {for (i=1;i<=n+10;i++) pre[i]=i,rnk[i]=1;}
inline int find_anc(int x) {if (pre[x]!=x) pre[x]=find_anc(pre[x]);return pre[x];}
inline void update(int x,int y)
{
x=find_anc(x);y=find_anc(y);
if (rnk[x]>=
4000
rnk[y])
{
pre[y]=x;
if (rnk[x]==rnk[y]) rnk[x]++;
}
else
pre[x]=y;
}
}

int main ()
{
int i,type,l,r,pos;
n=getint();q=getint();
for (i=1;i<=n;i++) a[i]=getint(),BIT::update(i,a[i]);
sieve();
for (i=1;i<=1000000;i++) d[i]=go(i);
DSU::init();
while (q--)
{
type=getint();l=getint();r=getint();
//for (i=1;i<=n;i++) cout<<BIT::calc(i,i)<<' ';
//cout<<endl;
//for (i=1;i<=n;i++) std::cout<<a[i]<<' ';
//std::cout<<endl;
if (type==1)
{
for (pos=DSU::find_anc(l);pos<=r;pos=DSU::find_anc(pos+1))
{
BIT::update(pos,d[a[pos]]-a[pos]);
a[pos]=d[a[pos]];
if (a[pos]<=2) DSU::update(pos,pos+1);
}
}
else
{
printf("%lld\n",BIT::calc(l,r));
}
}
return 0;
}