BZOJ4869: [Shoi2017] Meeting is a greeting

Topic meaning:

Maintain a sequence, support changing the number x in the interval to c^x, and sum the interval.

Solution:
Extended Euler's Theorem

a^b=a^(b%phi(p)+phi(p)) ( mod p )

Then because the base is determined, a number will not change at most log(x) times, because phi(p) becomes 1 after executing log(x) times

Line segment tree violence

Code:

#include<cstdio>
#include<algorithm>
using namespace std;
int n,mod,c,m,p,cnt,a[1000005],phi[1000005],tree[1000005],minn[1000005];
int get_phi(int x){
	int ans=x;
	for (int i=2; i*i<=x; i++)
		if (x%i==0){
			years=years/i*(i-1);
			while (x%i==0) x/=i;
		}
	if (x!=1) ans=ans/x*(x-1);
	return ans;
}
void build(int t,int l,int r){
	if (l==r){
		tree[t]=a[l];
		return;
	}
	int mid=(l+r)>>1;
	build(t<<1,l,mid);
	build(t<<1|1,mid+1,r);
	tree[t]=(tree[t<<1]+tree[t<<1|1])%mod;
}
int pow(int a,int b,int mod){
	int ans=1;
	while (b){
		if (b&1) ans=1ll*ans*a%mod;
		a=1ll*a*a%mod;
		b=b>>1;
	}
	return ans;
}
int query(int a,int times){
	for (int i=times; i>=1; i--){
		if (a>=phi[i]) a=a%phi[i]+phi[i];
		a=pow(c,a,phi[i-1]);
		if (!a) a=phi[i-1];
	}
	return a;
}
void change(int t,int l,int r,int x,int y){
	if (l>y || r<x) return;
	if (minn[t]>=cnt) return;
	if (l==r){
		from [t] ++;
		tree[t]=query(a[l],minn[t]);
		return;
	}
	int mid=(l+r)>>1;
	change(t<<1,l,mid,x,y);
	change(t<<1|1,mid+1,r,x,y);
	tree[t]=(tree[t<<1]+tree[t<<1|1])%mod;
	from [t] = min (from [t << 1], from [t << 1 | 1]);
}
int query (int t, int l, int r, int x, int y) {
	if (l>y || r<x) return 0;
	if (l>=x && r<=y) return tree[t];
	int mid=(l+r)>>1;
	return (query(t<<1,l,mid,x,y)+query(t<<1|1,mid+1,r,x,y))%mod;
}
int main(){
	scanf("%d%d%d%d",&n,&m,&p,&c);
	for (int i=1; i<=n; i++)
		scanf("%d",&a[i]);
	mod = phi [0] = p;
	while (p!=1){
		phi[++cnt]=get_phi(p);
		p=phi[cnt];
	}
	phi[++cnt]=1;
	build(1,1,n);
	while (m--){
		int cas, l, r;
		scanf("%d%d%d",&cas,&l,&r);
		if (cas==0) change(1,1,n,l,r);
		else printf("%d\n",query(1,1,n,l,r));
	}
	return 0;
}