万恶的TLE...
可在我机子上也就跑600ms,奇了怪了
数据无误
#include<iostream>
#include<algorithm>
#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<cmath>
#include<string>
#include<vector>
#include<stack>
#include<queue>
#include<set>
#include<map>
#include<ctime>
#define rep(i,j,k) for(register int i=j;i<=k;i++)
#define rrep(i,j,k) for(register int i=j;i>=k;i--)
#define erep(i,u) for(register int i=head[u];~i;i=nxt[i])
#define iin(a) scanf("%d",&a)
#define lin(a) scanf("%lld",&a)
#define din(a) scanf("%lf",&a)
#define s0(a) scanf("%s",a)
#define s1(a) scanf("%s",a+1)
#define print(a) printf("%lld",(ll)a)
#define enter putchar('\n')
#define blank putchar(' ')
#define println(a) printf("%lld\n",(ll)a)
#define IOS ios::sync_with_stdio(0)
using namespace std;
const int MAXN = 4e5+11;
const double EPS = 1e-7;
typedef long long ll;
typedef unsigned long long ull;
const ll MOD = 1e9+7;
unsigned int SEED = 17;
const ll INF = 1ll<<60;
ll read(){
ll x=0,f=1;register char ch=getchar();
while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
return x*f;
}
inline int Rand(){
SEED=SEED*1103515245+12345;
return SEED/65536;
}
ull p[MAXN];
int curlen;
struct Treap{
int son[MAXN][2],root,tot;
int val[MAXN],fix[MAXN],size[MAXN];
bool flip[MAXN];
ull Hash[MAXN][2];
int stk[MAXN];
#define lc son[o][0]
#define rc son[o][1]
void init(){
root=0;
son[0][0]=son[0][1]=0;
val[0]=fix[0]=size[0]=0;
flip[0]=0;
Hash[0][0]=Hash[0][1]=0;
tot=1;
}
int node(int v){
son[tot][0]=son[tot][1]=0;
val[tot]=v; fix[tot]=rand();
size[tot]=1;flip[tot]=0;
Hash[tot][0]=Hash[tot][1]=v;
return tot++;
}
void pu(int o){
size[o]=size[lc]+size[rc]+1;
Hash[o][0]=Hash[rc][0]+val[o]*p[size[rc]]+Hash[lc][0]*p[size[rc]+1];
Hash[o][1]=Hash[lc][1]+val[o]*p[size[lc]]+Hash[rc][1]*p[size[lc]+1];
}
void rev(int o){
swap(Hash[o][0],Hash[o][1]);
swap(lc,rc);
flip[o]^=1;
}
void pd(int o){
if(flip[o]){
if(lc) rev(lc);
if(rc) rev(rc);
flip[o]=0;
}
}
void split(int o,int k,int &a,int &b){
if(!o){
a=b=0;
return;
}else if(k<=size[lc]){
pd(o);
b=o;
split(lc,k,a,lc);
pu(o);
}else{
pd(o);
a=o;
split(rc,k-size[lc]-1,rc,b);
pu(o);
}
}
int merge(int a,int b){
if(!a) return b;
if(!b) return a;
if(a) pd(a); if(b) pd(b);
if(fix[a]<fix[b]){
son[a][1]=merge(son[a][1],b);
pu(a);
return a;
}else{
son[b][0]=merge(a,son[b][0]);
pu(b);
return b;
}
}
void insert(int pos,int v){
int a,b,t=node(v);
split(root,pos,a,b);
root=merge(merge(a,t),b);
}
int get(int pos){
int a,b,x,y;
split(root,pos-1,a,b);
split(b,1,x,y);
int t=x;
root=merge(a,merge(x,y));
return t;
}
void del(int pos){
int a,b,x,y;
split(root,pos-1,a,b);
split(b,1,x,y);
root=merge(a,y);
}
void revv(int pos,int len){//[pos,pos+len-1]
int a,b,x,y;
split(root,pos-1,a,b);
split(b,len,x,y);
rev(x);
root=merge(a,merge(x,y));
}
ull get(int pos,int len){
int a,b,x,y;
split(root,pos-1,a,b);
split(b,len,x,y);
ull ans=Hash[x][0];
root=merge(a,merge(x,y));
return ans;
}
bool C(int mid,int st1,int st2){
if(mid==0)return 0;
if(st1==0||st2==0)return 0;
return get(st1/*-mid+1*/,mid)==get(st2/*-mid+1*/,mid);
}
ll LCP(int a,int b){
if(a==b)return a;
int l=1,r=curlen-b+1,mid;
//鏋氫妇闀垮害
while(l<r){
mid=l+(r-l+1)/2;
if(C(mid,a,b))l=mid;
else r=mid-1;
}
return C(l,a,b)?l:0;
}
int build(char str[],int n){
int x,last=0,top=0;
rep(i,1,n){
x=node((int)str[i]),last=0;
while(top&&fix[stk[top]]>stk[x]){
pu(stk[top]),last=stk[top];
stk[top--]=0;
}
if(top) son[stk[top]][1]=x;
son[x][0]=last;
stk[++top]=x;
}
while(top){
pu(stk[top--]);
}
return stk[1];
}
}tp;
char str[MAXN];
int main(){
p[0]=1;
rep(i,1,MAXN-1) p[i]=p[i-1]*233;
int n,m;
while(~scanf("%d%d",&n,&m)){
s1(str);
curlen=n;
tp.init();
rep(i,1,n){
tp.insert(i,(int)str[i]);
}
rep(i,1,m){
int op=read();
int a,b;
switch(op){
case 1:
a=read();
b=read();
tp.insert(a,b+'0');
curlen++;
break;
case 2:
a=read();
tp.del(a);
curlen--;
break;
case 3:
a=read();
b=read();
tp.revv(a,b-a+1);
break;
case 4:
a=read();
b=read();
println(tp.LCP(a,b));
break;
}
}
}
return 0;
}