Query on a string 线段树

动态维护s1的所有区间内s2的个数

开始的想法是线段树区间保存有多少个完整的s2串，当成区间合并做，暂时没调出来bug：

#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 ull unsigned long long
#define pb push_back
#define FOR(a) for(int i=1;i<=a;i++)
const int inf=0x3f3f3f3f;
const ll Linf=9e18;
const int maxn=1e5+7; 
const ll mod=100003;
const double eps=1e-6;

/******************************************************/  
namespace fastIO{    
    #define BUF_SIZE 100000    
    #define OUT_SIZE 100000    
    #define ll long long    
    //fread->read    
    bool IOerror=0;    
    inline char nc(){    
        static char buf[BUF_SIZE],*p1=buf+BUF_SIZE,*pend=buf+BUF_SIZE;    
        if (p1==pend){    
            p1=buf; pend=buf+fread(buf,1,BUF_SIZE,stdin);    
        if (pend==p1){IOerror=1;return -1;}    
        //{printf("IO error!
");system("pause");for (;;);exit(0);}    
    }    
    return *p1++;    
}    
inline bool blank(char ch){return ch==' '||ch=='
'||ch=='
'||ch=='	';}    
inline void read(int &x){    
    bool sign=0; char ch=nc(); x=0;    
    for (;blank(ch);ch=nc());    
    if (IOerror)return;    
    if (ch=='-')sign=1,ch=nc();    
    for (;ch>='0'&&ch<='9';ch=nc())x=x*10+ch-'0';    
    if (sign)x=-x;    
}    
inline void read(ll &x){    
    bool sign=0; char ch=nc(); x=0;    
    for (;blank(ch);ch=nc());    
    if (IOerror)return;    
    if (ch=='-')sign=1,ch=nc();    
    for (;ch>='0'&&ch<='9';ch=nc())x=x*10+ch-'0';    
    if (sign)x=-x;    
}    
inline void read(double &x){    
    bool sign=0; char ch=nc(); x=0;    
    for (;blank(ch);ch=nc());    
    if (IOerror)return;    
    if (ch=='-')sign=1,ch=nc();    
    for (;ch>='0'&&ch<='9';ch=nc())x=x*10+ch-'0';    
    if (ch=='.'){    
        double tmp=1; ch=nc();    
        for (;ch>='0'&&ch<='9';ch=nc())tmp/=10.0,x+=tmp*(ch-'0');    
    }    
    if (sign)x=-x;    
}    
inline void read(char *s){    
    char ch=nc();    
    for (;blank(ch);ch=nc());    
    if (IOerror)return;    
    for (;!blank(ch)&&!IOerror;ch=nc())*s++=ch;    
    *s=0;    
}    
inline void read(char &c){    
    for (c=nc();blank(c);c=nc());    
    if (IOerror){c=-1;return;}    
}   
#undef OUT_SIZE    
#undef BUF_SIZE    
}; using namespace fastIO;  
/*****************************************************/  


int n;int len,len2;
char s1[maxn],s2[maxn];

struct NODE{
	int l,r;
	int val;
}ST[maxn<<2];

void pushup(int rt){
	ST[rt].val=ST[rt<<1].val+ST[rt<<1|1].val;
	int flag=0;
	for(int l=len2-1;l>=1;l--){

		if(ST[rt<<1].r-ST[rt<<1].l+1<l
		||ST[rt<<1|1].r-ST[rt<<1|1].l+1<len2-l	
		)continue;

		int pos=1;	
		int ok=1;		//这个分配是否可行
		int r=len2-l;	//左区间l个右区间r个
		for(int i= ST[rt<<1].r-l+1 ;i<=ST[rt<<1].r;i++){
			if(s1[i]==s2[pos]){
				pos++;
			}else{
				ok=0;break;
			}
		}
		if(ok==0)continue;
		for(int i=ST[rt<<1|1].l;i<=ST[rt<<1|1].l + r-1;i++){
			if(s1[i]==s2[pos]){
				pos++;
				if(pos>len2){
					break;
				}
			}else{
				ok=0;break;
			}
		}
		if(ok){flag++;}
	}
	if(flag)ST[rt].val+=flag;
}
void build(int l,int r,int rt){
	ST[rt].l=l;ST[rt].r=r;ST[rt].val=0;
	if(l==r){return;}
	int m=l+r>>1;
	build(l,m,rt<<1);build(m+1,r,rt<<1|1);pushup(rt);
}
void update(int a,char b,int l,int r,int rt){
	if(l==r){s1[a]=b;return;}
	int m=l+r>>1;
	if(a<=m)update(a,b,l,m,rt<<1);
	else update(a,b,m+1,r,rt<<1|1);
	pushup(rt);
}

int query(int a,int b,int l,int r,int rt){
	if(r<a || l>b)return 0;
	if(a<=l && b>=r){
		return ST[rt].val;
	}
	int m=l+r>>1;
	int ret=0;
	if(a<=m)ret+=query(a,b,l,m,rt<<1);
	if(b>m)ret+=query(a,b,m+1,r,rt<<1|1);

	int flag=0;
	if(a<=m && b>m && b-a+1>=len2){
		int pos=1;
		for(int l1=len2-1;l1>=1;l1--){
			int r1=len2-l1;	//左区间l1个右区间r1个
			if(ST[rt<<1].r-ST[rt<<1].l+1<l1
			||ST[rt<<1|1].r-ST[rt<<1|1].l+1<r1
			)continue;

			int ok=1;
			for(int i=ST[rt<<1].r-l1+1;i<=ST[rt<<1].r;i++){
				if(s1[i]==s2[pos]){
					pos++;
				}else{
					ok=0;break;
				}
			}
			if(!ok)continue;
			for(int i=ST[rt<<1|1].l;i<=ST[rt<<1|1].l+r1-1;i++){
				if(s1[i]==s2[pos]){
					pos++;
					if(pos>len2){break;}
				}else{
					ok=0;break;
				}
			}
			if(ok){
				flag++;
			}
		}	
	}
	if(flag)ret+=flag;
	return ret;	
}

char op[2];
int main(){
	int T;read(T);
	//scanf("%d",&T);
	while(T--){
		//scanf("%d",&n);
		read(n);
		//scanf("%s%s",s1+1,s2+1);
		read(s1+1);read(s2+1);
		len=strlen(s1+1);
		len2=strlen(s2+1);
		build(1,len,1);

		for(int i=1;i<=n;i++){
			//scanf("%s",op);
			read(op);
			if(op[0]=='Q'){
				int x,y;
				//scanf("%d%d",&x,&y);
				read(x);read(y);
				if(y-x+1<len2){
					printf("0
");continue;
				}
				printf("%d
",query(x,y,1,len,1));
			}else{
				int x;char ch[2];
				//scanf("%d%s",&x,ch);
				read(x);read(ch);
				if(ch[0]==s1[x])continue;
				update(x,ch[0],1,len,1);
			}
		}
		puts("");
	}
}

一个简单的做法是单点0,1表示作为头是否可以匹配，这个好写多了

#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 ull unsigned long long
#define pb push_back
#define FOR(a) for(int i=1;i<=a;i++)
const int inf=0x3f3f3f3f;
const ll Linf=9e18;
const int maxn=1e5+7; 
const ll mod=100003;
const double eps=1e-6;

/******************************************************/  
namespace fastIO{    
    #define BUF_SIZE 100000    
    #define OUT_SIZE 100000    
    #define ll long long    
    //fread->read    
    bool IOerror=0;    
    inline char nc(){    
        static char buf[BUF_SIZE],*p1=buf+BUF_SIZE,*pend=buf+BUF_SIZE;    
        if (p1==pend){    
            p1=buf; pend=buf+fread(buf,1,BUF_SIZE,stdin);    
        if (pend==p1){IOerror=1;return -1;}    
        //{printf("IO error!
");system("pause");for (;;);exit(0);}    
    }    
    return *p1++;    
}    
inline bool blank(char ch){return ch==' '||ch=='
'||ch=='
'||ch=='	';}    
inline void read(int &x){    
    bool sign=0; char ch=nc(); x=0;    
    for (;blank(ch);ch=nc());    
    if (IOerror)return;    
    if (ch=='-')sign=1,ch=nc();    
    for (;ch>='0'&&ch<='9';ch=nc())x=x*10+ch-'0';    
    if (sign)x=-x;    
}    
inline void read(ll &x){    
    bool sign=0; char ch=nc(); x=0;    
    for (;blank(ch);ch=nc());    
    if (IOerror)return;    
    if (ch=='-')sign=1,ch=nc();    
    for (;ch>='0'&&ch<='9';ch=nc())x=x*10+ch-'0';    
    if (sign)x=-x;    
}    
inline void read(double &x){    
    bool sign=0; char ch=nc(); x=0;    
    for (;blank(ch);ch=nc());    
    if (IOerror)return;    
    if (ch=='-')sign=1,ch=nc();    
    for (;ch>='0'&&ch<='9';ch=nc())x=x*10+ch-'0';    
    if (ch=='.'){    
        double tmp=1; ch=nc();    
        for (;ch>='0'&&ch<='9';ch=nc())tmp/=10.0,x+=tmp*(ch-'0');    
    }    
    if (sign)x=-x;    
}    
inline void read(char *s){    
    char ch=nc();    
    for (;blank(ch);ch=nc());    
    if (IOerror)return;    
    for (;!blank(ch)&&!IOerror;ch=nc())*s++=ch;    
    *s=0;    
}    
inline void read(char &c){    
    for (c=nc();blank(c);c=nc());    
    if (IOerror){c=-1;return;}    
}   
#undef OUT_SIZE    
#undef BUF_SIZE    
}; using namespace fastIO;  
/*****************************************************/  
int len1,len2;
char s1[maxn],s2[maxn];
char op[2],ch[2];
int x,y;
int arr[maxn];

int same;

struct NODE{
	int val;
}ST[maxn<<2];	//区间内有多少个头(

void pushup(int rt){ST[rt].val=ST[rt<<1].val+ST[rt<<1|1].val;}
void build(int l,int r,int rt){
	if(l==r){
		ST[rt].val=arr[l];return;
	}
	int m=l+r>>1;
	build(l,m,rt<<1);build(m+1,r,rt<<1|1);pushup(rt);
}
void update(int a,int b,int l,int r,int rt){	//区间[a,b]影响
	if(l>b || r<a)return;
	if(l+len2-1>len1)return;
	if(l==r){	//计算s1[l]作为头是1还是0

		int flag=1;
		for(int i=l;i<=l+len2-1;i++){
			//if(i>len1){flag=0;break;}
			if(s1[i]!=s2[i-l+1]){
				flag=0;break;
			}
		}
		if(flag)ST[rt].val=1;else ST[rt].val=0;
		return;
	}
	int m=l+r>>1;
	update(a,b,l,m,rt<<1);update(a,b,m+1,r,rt<<1|1);
	pushup(rt);
}
int query(int a,int b,int l,int r,int rt){
	if(a<=l&&b>=r)return ST[rt].val;
	int m=l+r>>1,ret=0;
	if(a<=m)ret=query(a,b,l,m,rt<<1);
	if(b>m)ret+=query(a,b,m+1,r,rt<<1|1);
	return ret;
}

int main(){
	int T;
	read(T);
	//scanf("%d",&T);
	while(T--){
		int n;
		//scanf("%d",&n);scanf("%s%s",s1+1,s2+1);
		read(n);
		read(s1+1);read(s2+1);
		len1=strlen(s1+1);len2=strlen(s2+1);

		for(int i=1;i<=len1-len2+1;i++){
			int flag=1;
			for(int j=i;j<=i+len2-1;j++){
				if(s1[j]!=s2[j-i+1]){
					flag=0;break;
				}
			}
			if(flag)arr[i]=1;else arr[i]=0;
		}
		build(1,len1,1);

		while(n--){
			read(op);
			//scanf("%s",op);
			if(op[0]=='Q'){
				read(x);read(y);
				//scanf("%d%d",&x,&y);
				if(y-x+1<len2){
					printf("0
");continue;
				}
				printf("%d
",query(x,y-len2+1,1,len1,1));
			}else{
				read(x);read(ch);
				//scanf("%d%s",&x,ch);
				if(ch[0]!=s1[x])same=0;
				else same=1;
				if(same)continue;
				s1[x]=ch[0];
				update(max(1,x-len2+1),x,1,len1,1);
			}
		}
		puts("");
	}
}