珂朵莉树板子，我觉得讲的就很不错

粘一下自己的板子

#include
    
     #define re register#define LL long long#define ST std::set
     
      ::iteratorinline int ksm(int a,int b,int mod) {    int S=1;    for(;b;b>>=1,a=1ll*a*a%mod) if(b&1) S=1ll*S*a%mod;    return S;}const int MOD7=1000000007;struct node {    int l,r;    mutable LL v;    bool operator<(const node &A) const{if(l==A.l) return r
      
        s;int n,m,seed,vmax;inline int rnd() {    int ret=seed;    seed=(seed*7ll+13)%MOD7;    return ret;}inline ST split(int pos) {    ST it=s.lower_bound((node){pos,-1,0});    if(it!=s.end()&&it->l==pos) return it;    --it;    int L=it->l,R=it->r;LL t=it->v;    s.erase(it);    s.insert((node){L,pos-1,t});    return s.insert((node){pos,R,t}).first;}inline void pia(int l,int r,int v) {    ST itl=split(l),itr=split(r+1);    s.erase(itl,itr);    s.insert((node){l,r,(LL)v});}inline void add(int l,int r,int t) {    ST itl=split(l),itr=split(r+1);    for(;itl!=itr;++itl) itl->v+=t;}inline int calc(int l,int r,int x,int mod) {    ST itl=split(l),itr=split(r+1);    int ans=0;    for(;itl!=itr;++itl)         ans=(ans+1ll*ksm(itl->v%mod,x,mod)*(itl->r-itl->l+1)%mod)%mod;    return ans; }inline LL rk(int l,int r,int k) {    ST itl=split(l),itr=split(r+1);    int cnt=0;    for(;itl!=itr;++itl) a[++cnt].v=itl->v,a[cnt].t=itl->r-itl->l+1;    std::sort(a+1,a+cnt+1,cmp);    for(re int i=1;i<=cnt;i++) {        if(k-a[i].t>0) {k-=a[i].t;continue;}        return a[i].v;    }}int main() {    //scanf("%d%d%lld%lld",&n,&m,&seed,&vmax);    std::cin>>n>>m>>seed>>vmax;    for(re int i=1;i<=n;i++) s.insert((node){i,i,rnd()%vmax+1});    int op,l,r,x,y;    for(re int i=1;i<=m;i++) {        op=rnd()%4+1;        l=rnd()%n+1;r=rnd()%n+1;        if(l>r) std::swap(l,r);        if(op==3) x=rnd()%(r-l+1)+1;            else x=rnd()%vmax+1;        if(op==4) y=rnd()%vmax+1;        if(op==1) add(l,r,x);        if(op==2) pia(l,r,x);        if(op==4) printf("%d\n",calc(l,r,x,y));        if(op==3) std::cout<