Lvat_s Blog

状压DP

f[i][j][k]表示当前在第i行，包括第i行一共放了j个国王，而且这一行状态为k的方案数

那么f[i][j][k]=Sigma(f[i-1][j-cnt[l]][l],其中l为一种可行方案且不和k状态冲突)

然后搞个ans加一下就没了

#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;

long long n,K,cnt[1<<10],f[15][105][1<<10],rule[1<<10],ed,ans;

int Cnt(int s){
int ans=0;
while(s){
	ans+=s&1;
	s>>=1;
}
return ans;
}

int CheckNot(int s,int l){
return (s&l)||(s&(l>>1))||(s&(l<<1));
}

int CheckGood(int s){
int flg=0;
while(s){
	if(s&1 && flg)return 0;
	flg=s&1;
	s>>=1;
}
return 1;
}

void Get(){
for(int i=0;i<=ed;i++){cnt[i]=Cnt(i);rule[i]=CheckGood(i);}
}

int main(){
freopen("1087.in","r",stdin);
freopen("1087.out","w",stdout);
scanf("%lld %lld",&n,&K);
ed=(1<<n)-1;
Get();
for(int i=0;i<=ed;i++)if(rule[i])f[1][cnt[i]][i]=1;
for(int i=2;i<=n;i++){
	for(int j=0;j<=ed;j++){
		if(!rule[j])continue;
        for(int k=0;k<=ed;k++){
			if(!rule[k] || CheckNot(j,k))continue;
			for(int l=cnt[k];l+cnt[j]<=K;l++)f[i][l+cnt[j]][j]+=f[i-1][l][k];
        }
	}
}
for(int i=0;i<=ed;i++)ans+=f[n][K][i];
printf("%lld\n",ans);
return 0;
}

m<=2。。。

所以直接DP

m=1时

f[i][1][k]表示这一列前i个数选了k个子矩阵(中间的1没有用处)

那么转移就很像最大子段和:f[i][1][k]=max(f[i-1][1][k],f[j][1][k-1]+sum[i]-sum[j]);

前面表示不选择，后面表示选择j-i这一段所能带来的当前情况下的最大得分

m=2时复杂一些

f[i][j][k]表示第一列前i个数第二列前j个数选了k个子矩阵

那么转移分4种情况

1:f[i][j][k]=max(f[i-1][j][k],f[i][j-1][k]);表示继承上一个状态的结果，不选择i或者j

2:f[i][j][k]=max(f[i][j][k],f[ix][j][k-1]+sum[i][1]-sum[ix][1]);表示选择ix-i这一段所能带来的当前情况下的最大得分

3:f[i][j][k]=max(f[i][j][k],f[i][jx][k-1]+sum[j][2]-sum[jx][2]);表示选择jx-j这一段所能带来的当前情况下的最大得分

4:if(i==j)f[i][j][k]=max(f[i][j][k],f[x][x][k-1]+sum[i][1]-sum[x][1]+sum[j][2]-sum[x][2]);表示同时选择两排所能带来的最大得分

最后输出f[n][n][k]就可以了，表示第一列和第二列都选完了，一共选择了k个子矩阵

难得写一次详细的题解……主要是因为我在狂补DP,DP渣到连前几年的普及组题目都写不出来……

去年NOIP D2T2居然不会写

这都坚定了我要补DP的决心……

#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;

int sum[105][5],f[105][105][15],a[105][5],n,m,K;

int main(){
freopen("1084.in","r",stdin);
freopen("1084.out","w",stdout);
scanf("%d %d %d",&n,&m,&K);
for(int i=1;i<=n;i++){
	for(int j=1;j<=m;j++){
		scanf("%d",&a[i][j]);
		sum[i][j]=sum[i-1][j]+a[i][j];
	}
}
memset(f,-127,sizeof(f));
if(m==1){
	for(int i=0;i<=n;i++)f[i][1][0]=0;
	for(int i=1;i<=n;i++){
		for(int k=1;k<=K;k++){
			f[i][1][k]=f[i-1][1][k];
			for(int j=0;j<i;j++){
				f[i][1][k]=max(f[i][1][k],f[j][1][k-1]+sum[i][1]-sum[j][1]);
			}
		}
	}
	printf("%d\n",f[n][1][K]);
}
else if(m==2){
	for(int i=0;i<=n;i++)for(int j=0;j<=n;j++)f[i][j][0]=0;
	for(int i=1;i<=n;i++){
		for(int j=1;j<=n;j++){
			for(int k=1;k<=K;k++){
				f[i][j][k]=max(f[i-1][j][k],f[i][j-1][k]);
				for(int ix=0;ix<i;ix++)f[i][j][k]=max(f[i][j][k],f[ix][j][k-1]+sum[i][1]-sum[ix][1]);
				for(int jx=0;jx<j;jx++)f[i][j][k]=max(f[i][j][k],f[i][jx][k-1]+sum[j][2]-sum[jx][2]);
				if(i==j)for(int x=0;x<i;x++)f[i][j][k]=max(f[i][j][k],f[x][x][k-1]+sum[i][1]-sum[x][1]+sum[j][2]-sum[x][2]);
			}
		}
	}
	printf("%d\n",f[n][n][K]);
}
return 0;
}

又做了一道叫"tree"的题目。。

这题要开unsigned int!!!!

开int会WA!开int会WA!开int会WA!重要的事说三遍

#include<cstdio>
#include<algorithm>
using namespace std;

unsigned int n,q;

struct Node{
unsigned int v,sum,add,rev,mul,siz;
Node *ch[2],*fa;
Node(unsigned int val,Node *fat);
void Pushdown();
void Pushup();
}*root[100005],*Null;

Node::Node(unsigned int val,Node *fat){
v=sum=val;
mul=siz=1;
add=rev=0;
ch[0]=ch[1]=Null;
fa=fat;
}

void Node::Pushdown(){
if(rev){
	rev=0;
	if(ch[0]!=Null)ch[0]->rev^=1;
	if(ch[1]!=Null)ch[1]->rev^=1;
	swap(ch[0]->ch[0],ch[0]->ch[1]);
	swap(ch[1]->ch[0],ch[1]->ch[1]);
}
if(mul!=1){
	if(ch[0]!=Null){
		ch[0]->mul=(ch[0]->mul*mul)%51061;
		ch[0]->add=(ch[0]->add*mul)%51061;
		ch[0]->sum=(ch[0]->sum*mul)%51061;
		ch[0]->v=(ch[0]->v*mul)%51061;
	}
	if(ch[1]!=Null){
		ch[1]->mul=(ch[1]->mul*mul)%51061;
		ch[1]->add=(ch[1]->add*mul)%51061;
		ch[1]->sum=(ch[1]->sum*mul)%51061;
		ch[1]->v=(ch[1]->v*mul)%51061;
	}
	mul=1;
}
if(add){
	if(ch[0]!=Null){
		ch[0]->add=(ch[0]->add+add)%51061;
		ch[0]->sum=(ch[0]->sum+ch[0]->siz%51061*add)%51061;
		ch[0]->v=(ch[0]->v+add)%51061;
	}
	if(ch[1]!=Null){
		ch[1]->add=(ch[1]->add+add)%51061;
		ch[1]->sum=(ch[1]->sum+ch[1]->siz%51061*add)%51061;
		ch[1]->v=(ch[1]->v+add)%51061;
	}
	add=0;
}
}

void Node::Pushup(){
siz=1;
sum=v;
if(ch[0]!=Null){siz+=ch[0]->siz;sum=(sum+ch[0]->sum)%51061;}
if(ch[1]!=Null){siz+=ch[1]->siz;sum=(sum+ch[1]->sum)%51061;}
}

int Notroot(Node *p){
return (p->fa->ch[0]==p)||(p->fa->ch[1]==p);
}

void Prepare(Node *p){
if(Notroot(p))Prepare(p->fa);
p->Pushdown();
}

void Rotate(Node *x,int kind){
Node *y=x->fa,*z=y->fa;
y->ch[!kind]=x->ch[kind];
if(x->ch[kind]!=Null)x->ch[kind]->fa=y;
x->fa=z;
if(Notroot(y))z->ch[z->ch[1]==y]=x;
y->fa=x;
x->ch[kind]=y;
y->Pushup();
x->Pushup();
}

void Splay(Node *x){
Prepare(x);
while(Notroot(x)){
	Node *y=x->fa,*z=y->fa;
	if(!Notroot(y))Rotate(x,y->ch[0]==x);
	else {
		if(y->ch[0]==x && z->ch[0]==y){Rotate(y,1);Rotate(x,1);}
		else if(y->ch[0]==x && z->ch[1]==y){Rotate(x,1);Rotate(x,0);}
		else if(y->ch[1]==x && z->ch[0]==y){Rotate(x,0);Rotate(x,1);}
		else {Rotate(y,0);Rotate(x,0);}
	}
}
}

void Access(Node *x){
for(Node *y=Null;x!=Null;y=x,x=x->fa){Splay(x);x->ch[1]=y;x->Pushup();}
}

void Makeroot(Node *x){
Access(x);
Splay(x);
x->rev^=1;
swap(x->ch[0],x->ch[1]);
}

void Link(Node *x,Node *y){
Makeroot(x);
x->fa=y;
}

void Cut(Node *x,Node *y){
Makeroot(x);
Access(y);
Splay(y);
if(y->ch[0]==x){x->fa=Null;y->ch[0]=Null;}
}

Node *Find(Node *x){
Access(x);
Splay(x);
while(x->ch[0]!=Null)x=x->ch[0];
return x;
}

Node *ToLct(int x){
return root[x];
}

Node *GetNull(){
Node *p=new Node(0,Null);
p->ch[0]=p->ch[1]=p->fa=p;
p->siz=0;
return p;
}

void Add(int x,int y,int z){
Node *p=ToLct(x),*q=ToLct(y);
Makeroot(p);
Access(q);
Splay(q);
q->add=(q->add+z)%51061;
q->v=(q->v+z)%51061;
q->Pushup();
}

void Mul(int x,int y,int z){
Node *p=ToLct(x),*q=ToLct(y);
Makeroot(p);
Access(q);
Splay(q);
q->mul=(q->mul*z)%51061;
q->v=(q->v*z)%51061;
q->Pushup();
}

unsigned int Div(int x,int y){
Node *p=ToLct(x),*q=ToLct(y);
Makeroot(p);
Access(q);
Splay(q);
return q->sum;
}

int main(){
freopen("2631.in","r",stdin);
freopen("2631.out","w",stdout);
scanf("%d %d",&n,&q);
Null=GetNull();
for(int i=1;i<=n;i++)root[i]=new Node(1,Null);
for(int i=1;i<n;i++){
	int u,v;
    scanf("%d %d",&u,&v);
    Link(ToLct(u),ToLct(v));
}
for(int i=1;i<=q;i++){
    char s[3];
    scanf("%s",s);
    if(s[0]=='+'){
		int u,v,c;
		scanf("%d %d %d",&u,&v,&c);
		Add(u,v,c);
    }
    if(s[0]=='-'){
		int u1,v1,u2,v2;
		scanf("%d %d %d %d",&u1,&v1,&u2,&v2);
        Cut(ToLct(u1),ToLct(v1));
        Link(ToLct(u2),ToLct(v2));
    }
    if(s[0]=='*'){
		int u,v,c;
		scanf("%d %d %d",&u,&v,&c);
		Mul(u,v,c);
    }
    if(s[0]=='/'){
		int u,v;
		scanf("%d %d",&u,&v);
		printf("%d\n",Div(u,v));
    }
}
return 0;
}

怎么说呢……神奇的二分

每次把白色边加上一个二分的权值，再做最小生成树

如果大于need条边就说明加上的权值太小了需要增大

反之亦然(因为题目保证有解，所以必然会存在这样的一个权值)

注意排序时权值相等时白色边放在前面

#include<cstdio>
#include<algorithm>
using namespace std;

int V,E,need,f[100005],test=0,ne=0;

struct Edge{
int a,b,v,co;
friend bool operator<(Edge a,Edge b){
return a.v==b.v?a.co<b.co:a.v<b.v;
}
}e[100005];

int Find(int x){return x==f[x]?x:f[x]=Find(f[x]);}
void Union(int sa,int sb){
if(sa<sb)f[sb]=sa;
else f[sa]=sb;
}

int Check(int ans){
test=ne=0;
for(int i=1;i<=V;i++)f[i]=i;
for(int i=1;i<=E;i++){
	if(!e[i].co)e[i].v+=ans;
}
sort(e+1,e+E+1);
for(int i=1;i<=E;i++){
	if(Find(e[i].a)!=Find(e[i].b)){
		Union(Find(e[i].a),Find(e[i].b));
		test+=e[i].v;
		if(!e[i].co)ne++;
	}
}
for(int i=1;i<=E;i++){
	if(!e[i].co)e[i].v-=ans;
}
return ne>=need;
}

int main(){
freopen("2654.in","r",stdin);
freopen("2654.out","w",stdout);
scanf("%d %d %d",&V,&E,&need);
for(int i=1;i<=E;i++){
	scanf("%d %d %d %d",&e[i].a,&e[i].b,&e[i].v,&e[i].co);
	e[i].a++;
	e[i].b++;
}
int l=-105,r=105,ans;
while(l<=r){
	int mid=l+r>>1;
	if(Check(mid)){ans=test-need*mid;l=mid+1;}
	else r=mid-1;
}
printf("%d\n",ans);
return 0;
}

最大流

拆点，男孩和女孩各拆成2个点ix,iy,jx,jy，互相喜欢ix->jx:1 不互相喜欢iy->jy:1

然后ix->iy=k,jy->jx=k,S->ix=ans,jy->T=ans

枚举ans跑最大流，不满流答案就是ans-1

#include<cstdio>
#include<queue>
#include<algorithm>
#include<cstring>
using namespace std;
 
int en,n,k,level[1005],S,T,cur[1005],POINT_N,h[1005];
char s[55][55];
 
struct Edge{
int b,f,back,next;
}e[1000005];
 
void AddEdge(int sa,int sb,int sc){
e[++en].b=sb;
e[en].f=sc;
e[en].back=en+1;
e[en].next=h[sa];
h[sa]=en;
swap(sa,sb);
e[++en].b=sb;
e[en].f=0;
e[en].back=en-1;
e[en].next=h[sa];
h[sa]=en;
}
 
int BFS(){
queue<int> Q;
Q.push(S);
memset(level,0,sizeof(level));
level[S]=1;
while(!Q.empty()){
    int u=Q.front();
    Q.pop();
    for(int i=h[u];i;i=e[i].next){
        int v=e[i].b;
        if(level[v] || !e[i].f)continue;
        level[v]=level[u]+1;
        Q.push(v);
    }
}
return level[T];
}
 
int DFS(int u,int flow){
if(u==T)return flow;
int f=flow;
for(int &i=cur[u];i;i=e[i].next){
    int v=e[i].b,fl;
    if(level[v]==level[u]+1 && e[i].f && (fl=DFS(v,min(f,e[i].f)))){
        e[i].f-=fl;
        e[e[i].back].f+=fl;
        f-=fl;
        if(f==0)return flow;
    }
}
return flow-f;
}
 
int Dinic(){
int ans=0;
while(BFS()){
    for(int i=1;i<=POINT_N;i++)cur[i]=h[i];
    ans+=DFS(S,2100000000);
}
return ans;
}
 
int main(){
freopen("1305.in","r",stdin);
freopen("1305.out","w",stdout);
scanf("%d %d",&n,&k);
for(int i=1;i<=n;i++)scanf("%s",s[i]+1);
S=4*n+1;
T=4*n+2;
POINT_N=4*n+2;
int ans=1;
while(ans<=1000){
    memset(h,0,sizeof(h));
    for(int i=1;i<=n;i++){
        AddEdge(i,i+n,k);
        AddEdge(i+3*n,i+2*n,k);
    }
    for(int i=1;i<=n;i++){
        for(int j=1;j<=n;j++){
            if(s[i][j]=='Y'){
                AddEdge(i,j+2*n,1);
            }
            else {
                AddEdge(i+n,j+3*n,1);
            }
        }
    }
    for(int i=1;i<=n;i++){
        AddEdge(S,i,ans);
        AddEdge(i+2*n,T,ans);
    }
    int an=Dinic();
    //printf("%d\n",ans);
    if(an<ans*n){printf("%d\n",ans-1);return 0;}
    ans++;
}
return 0;
}


这题有2问

第一问SPFA

第二问先从1->n 求一遍最短路，再从n->1求一遍最短路，然后判定每条边是否可能在最短路上

即D[e[i].a]+Di[e[i].b]+e[i].t==ans

注意每条边的反向边也需要判断一下

然后跑一遍最大流就行了（最小割=最大流）

#include<cstdio>
#include<cstring>
#include<queue>
#include<algorithm>
using namespace std;

int h[505],n,m,en,en1,D[505],Di[505],flag[505],S,T,cur[505];

struct Es{
int a,b,t,c;
}E[200005];

struct Edge1{
int b,v,next;
}e1[300005];

struct Edge{
int b,f,next,back;
}e[300005];

void AddEdge1(int sa,int sb,int sc){
e1[++en1].b=sb;
e1[en1].v=sc;
e1[en1].next=h[sa];
h[sa]=en1;
}

void AddEdge(int sa,int sb,int sc){
e[++en].b=sb;
e[en].f=sc;
e[en].next=h[sa];
e[en].back=en+1;
h[sa]=en;
swap(sa,sb);
e[++en].b=sb;
e[en].f=0;
e[en].next=h[sa];
e[en].back=en-1;
h[sa]=en;
}

int Spfa(int S,int T){
queue<int> Q;
memset(D,127,sizeof(D));
memset(flag,0,sizeof(flag));
Q.push(S);
D[S]=0;
flag[S]=1;
while(!Q.empty()){
	int u=Q.front();
	Q.pop();
	flag[u]=0;
	for(int i=h[u];i;i=e1[i].next){
		int v=e1[i].b;
		if(D[u]+e1[i].v<D[v]){
			D[v]=D[u]+e1[i].v;
            if(!flag[v]){
				Q.push(v);
				flag[v]=1;
            }
		}
	}
}
return D[T];
}

int Spfa2(int S,int T){
queue<int> Q;
memset(Di,127,sizeof(Di));
memset(flag,0,sizeof(flag));
Q.push(S);
Di[S]=0;
flag[S]=1;
while(!Q.empty()){
	int u=Q.front();
	Q.pop();
	flag[u]=0;
	for(int i=h[u];i;i=e1[i].next){
		int v=e1[i].b;
		if(Di[u]+e1[i].v<Di[v]){
			Di[v]=Di[u]+e1[i].v;
            if(!flag[v]){
				Q.push(v);
				flag[v]=1;
            }
		}
	}
}
return Di[T];
}

int Bfs(){
queue<int> Q;
Q.push(S);
memset(flag,0,sizeof(flag));
flag[S]=1;
while(!Q.empty()){
	int u=Q.front();
	Q.pop();
	for(int i=h[u];i;i=e[i].next){
		int v=e[i].b;
		if(flag[v] || !e[i].f)continue;
		flag[v]=flag[u]+1;
		Q.push(v);
	}
}
return flag[T];
}

int Dfs(int u,int flow){
if(u==T)return flow;
int f=flow;
for(int &i=cur[u];i;i=e[i].next){
	int v=e[i].b,fl;
	if(flag[v]==flag[u]+1 && e[i].f && (fl=Dfs(v,min(f,e[i].f)))){
		f-=fl;
		e[i].f-=fl;
		e[e[i].back].f+=fl;
		if(f==0)return flow;
	}
}
return flow-f;
}

int Dinic(){
int ans=0;
while(Bfs()){
	for(int i=1;i<=n;i++)cur[i]=h[i];
	ans+=Dfs(S,2100000000);
}
return ans;
}

int main(){
freopen("1266.in","r",stdin);
freopen("1266.out","w",stdout);
scanf("%d %d",&n,&m);
for(int i=1;i<=m;i++){
	scanf("%d %d %d %d",&E[i].a,&E[i].b,&E[i].t,&E[i].c);
	AddEdge1(E[i].a,E[i].b,E[i].t);
	AddEdge1(E[i].b,E[i].a,E[i].t);
}
int ans1=Spfa(1,n),ans2=Spfa2(n,1);
memset(h,0,sizeof(h));
printf("%d\n",ans1);
for(int i=1;i<=m;i++){
	if(D[E[i].a]+Di[E[i].b]+E[i].t==ans1){AddEdge(E[i].a,E[i].b,E[i].c);}
	if(Di[E[i].a]+D[E[i].b]+E[i].t==ans1){AddEdge(E[i].b,E[i].a,E[i].c);}
}
S=1;T=n;
ans2=Dinic();
printf("%d\n",ans2);
return 0;
}

这题写了我1.5h……

以后写题目必须认真、仔细！

Pushdown居然写错了……调试了半天

所以以后必须仔细想好细节再写，这样才能节省时间。

#include<cstdio>
#include<algorithm>
using namespace std;

int n,move_to=0;
char s[2000005];

struct Node{
char v;
int rev,siz;
Node *ch[2],*fa;
Node(char ch,Node *fat);
void Pushdown();
void Pushup();
}*root,*Null;

Node::Node(char c,Node *fat=Null){
ch[0]=ch[1]=Null;
fa=fat;
siz=1;
rev=0;
v=c;
}

void Node::Pushdown(){
if(rev){
	rev=0;
	if(ch[0]!=Null)ch[0]->rev^=1;
	if(ch[1]!=Null)ch[1]->rev^=1;
	swap(ch[0]->ch[0],ch[0]->ch[1]);
	swap(ch[1]->ch[0],ch[1]->ch[1]);
}
}

void Node::Pushup(){
siz=1;
if(ch[0]!=Null)siz+=ch[0]->siz;
if(ch[1]!=Null)siz+=ch[1]->siz;
}

void Rotate(Node *x,int kind){
Node *y=x->fa,*z=y->fa;
y->ch[!kind]=x->ch[kind];
if(x->ch[kind]!=Null)x->ch[kind]->fa=y;
x->fa=z;
if(z!=Null)z->ch[z->ch[1]==y]=x;
y->fa=x;
x->ch[kind]=y;
y->Pushup();
x->Pushup();
}

void Splay(Node *x,Node *place){
while(x->fa!=place){
	Node *y=x->fa,*z=y->fa;
	if(z==Null || z==place)Rotate(x,y->ch[0]==x);
	else {
		if(y->ch[1]==x && z->ch[1]==y){Rotate(y,0);Rotate(x,0);}
		else if(y->ch[1]==x && z->ch[0]==y){Rotate(x,0);Rotate(x,1);}
		else if(y->ch[0]==x && z->ch[1]==y){Rotate(x,1);Rotate(x,0);}
		else {Rotate(y,1);Rotate(x,1);}
	}
}
if(place==Null)root=x;
}

Node *Find(Node *splay,int k){
splay->Pushdown();
if(k==splay->ch[0]->siz+1)return splay;
if(k<=splay->ch[0]->siz)return Find(splay->ch[0],k);
return Find(splay->ch[1],k-1-splay->ch[0]->siz);
}

Node *Split(int pos,int tot){
Node *x=Find(root,pos),*y=Find(root,pos+tot+1);
Splay(x,Null);
Splay(y,root);
return y->ch[0];
}

Node *Build(int l,int r){
if(l>r)return Null;
int mid=l+r>>1;
Node *splay=new Node(s[mid],Null);
splay->ch[0]=Build(l,mid-1);
if(splay->ch[0]!=Null)splay->ch[0]->fa=splay;
splay->ch[1]=Build(mid+1,r);
if(splay->ch[1]!=Null)splay->ch[1]->fa=splay;
splay->Pushup();
return splay;
}

void Del_Tree(Node *splay){
if(splay==Null)return;
splay->Pushdown();
Del_Tree(splay->ch[0]);
Del_Tree(splay->ch[1]);
if(splay->ch[0]!=Null)delete splay->ch[0];
if(splay->ch[1]!=Null)delete splay->ch[1];
splay->ch[0]=Null;
splay->ch[1]=Null;
splay->Pushup();
}

Node *GetNull(){
Node *p=new Node('#',Null);
p->ch[0]=p->ch[1]=p->fa=p;
p->siz=p->rev=0;
}

void Build_First(){
Null=GetNull();
s[1]='H';
s[2]='i';
root=Build(1,2);
}

void Insert(int pos,int tot){
Node *x=Find(root,pos+1),*y=Find(root,pos+2);
Splay(x,Null);Splay(y,root);
y->ch[0]=Build(1,tot);
if(y->ch[0]!=Null)y->ch[0]->fa=y;
y->Pushup();
x->Pushup();
}

void Delete(int pos,int tot){
Node *seq=Split(pos,tot),*fat=seq->fa;
Del_Tree(seq);
if(seq!=Null)delete seq;
fat->ch[0]=Null;
fat->Pushup();
fat->fa->Pushup();
}

void Reverse(int pos,int tot){
Node *seq=Split(pos,tot),*fat=seq->fa;
seq->rev^=1;
swap(seq->ch[0],seq->ch[1]);
fat->Pushup();
fat->fa->Pushup();
}

char GetKey(int pos){
Node *u=Split(pos,1);
return u->v;
}

void GetString(int len){
char ch;
while((ch=getchar())=='\n');
s[1]=ch;
for(int i=2;i<=len;i++){s[i]=getchar();}
s[len+1]='\0';
}

int main(){
freopen("1269.in","r",stdin);
freopen("1269.out","w",stdout);
scanf("%d",&n);
Build_First();
for(int i=1;i<=n;i++){
	char opt[10];
	scanf("%s",opt);
	if(opt[0]=='M'){
		int k;
		scanf("%d",&k);
		move_to=k;
	}
	if(opt[0]=='I'){
		int tot;
		scanf("%d",&tot);
		GetString(tot);
		Insert(move_to,tot);
	}
	if(opt[0]=='D'){
		int tot;
		scanf("%d",&tot);
        Delete(move_to+1,tot);
	}
	if(opt[0]=='R'){
		int tot;
		scanf("%d",&tot);
		Reverse(move_to+1,tot);
	}
	if(opt[0]=='G'){
        printf("%c\n",GetKey(move_to+1));
	}
	if(opt[0]=='P')move_to--;
	if(opt[0]=='N')move_to++;
}
return 0;
}

两个都是可持久化线段树，相当于复习一下算法。。

第一个程序我没加路径压缩，第二个加了

第二个读入的操作编号不要异或lastans……在这里卡了一下

#include<cstdio>
#include<algorithm>
using namespace std;

struct SegTree{
int l,r,ls,rs,v;
}tree[2000005];

int root[20005],cnt,deep[200005],n,m;

void Build(int &rt,int l,int r){
if(!rt)rt=++cnt;
if(l==r){tree[rt].v=l;return;}
int mid=l+r>>1;
tree[rt].l=l;
tree[rt].r=r;
Build(tree[rt].ls,l,mid);
Build(tree[rt].rs,mid+1,r);
}

void Change(int x,int &y,int pos,int val){
y=++cnt;
tree[y].l=tree[x].l;
tree[y].r=tree[x].r;
if(tree[x].l==tree[x].r){tree[y].v=val;deep[y]=deep[x];return;}
tree[y].ls=tree[x].ls;
tree[y].rs=tree[x].rs;
int mid=tree[x].l+tree[x].r>>1;
if(pos<=mid)Change(tree[x].ls,tree[y].ls,pos,val);
if(pos>mid)Change(tree[x].rs,tree[y].rs,pos,val);
}

int Query(int rt,int pos){
if(tree[rt].l==tree[rt].r)return rt;
int mid=tree[rt].l+tree[rt].r>>1;
if(pos<=mid)return Query(tree[rt].ls,pos);
if(pos>mid)return Query(tree[rt].rs,pos);
}

void Add(int rt,int pos){
if(tree[rt].l==tree[rt].r){deep[rt]++;return;}
int mid=tree[rt].l+tree[rt].r>>1;
if(pos<=mid)Add(tree[rt].ls,pos);
if(pos>mid)Add(tree[rt].rs,pos);
}

int Find(int rt,int x){
int tp=Query(rt,x);
if(x==tree[tp].v)return tp;
return Find(rt,tree[tp].v);
}

int main(){
freopen("3673.in","r",stdin);
freopen("3673.out","w",stdout);
scanf("%d %d",&n,&m);
Build(root[0],1,n);
for(int i=1;i<=m;i++){
    int opt;
    scanf("%d",&opt);
    if(opt==1){
		int x,y,px,py;
        scanf("%d %d",&x,&y);
        root[i]=root[i-1];
        px=Find(root[i],x);py=Find(root[i],y);
        if(tree[px].v==tree[py].v)continue;
        if(deep[px]>deep[py])swap(px,py);
        Change(root[i-1],root[i],tree[px].v,tree[py].v);
        if(deep[px]==deep[py])Add(root[i],tree[py].v);
    }
    if(opt==2){
		int k;
		scanf("%d",&k);
		root[i]=root[k];
    }
    if(opt==3){
		int x,y;
		root[i]=root[i-1];
		scanf("%d %d",&x,&y);
		if(tree[Find(root[i],x)].v!=tree[Find(root[i],y)].v)puts("0");
		else puts("1");
    }
}
return 0;
}

#include<cstdio>
#include<algorithm>
using namespace std;

int n,m,cnt,lastans=0,deep[10000005],root[200005];

struct SegTree{
int l,r,ls,rs,v;
}tree[10000005];

void Build(int &rt,int l,int r){
if(!rt)rt=++cnt;
tree[rt].l=l;
tree[rt].r=r;
if(l==r){tree[rt].v=l;return;}
int mid=l+r>>1;
Build(tree[rt].ls,l,mid);
Build(tree[rt].rs,mid+1,r);
}

void Change(int x,int &y,int pos,int val){
y=++cnt;
tree[y].l=tree[x].l;
tree[y].r=tree[x].r;
if(tree[x].l==tree[x].r){tree[y].v=val;deep[y]=deep[x];return;}
tree[y].ls=tree[x].ls;
tree[y].rs=tree[x].rs;
int mid=tree[x].l+tree[x].r>>1;
if(pos<=mid)Change(tree[x].ls,tree[y].ls,pos,val);
if(pos>mid)Change(tree[x].rs,tree[y].rs,pos,val);
}

void Add(int rt,int pos){
if(tree[rt].l==tree[rt].r){deep[rt]++;return;}
int mid=tree[rt].l+tree[rt].r>>1;
if(pos<=mid)Add(tree[rt].ls,pos);
if(pos>mid)Add(tree[rt].rs,pos);
}

int Query(int rt,int pos){
if(tree[rt].l==tree[rt].r){return rt;}
int mid=tree[rt].l+tree[rt].r>>1;
if(pos<=mid)return Query(tree[rt].ls,pos);
if(pos>mid)return Query(tree[rt].rs,pos);
}

int Find(int rt,int x){
int p=Query(rt,x);
if(x==tree[p].v){return p;}
int tp=Find(rt,tree[p].v);
Change(rt,rt,tree[p].v,tp);
return tp;
}

int main(){
freopen("3674.in","r",stdin);
freopen("3674.out","w",stdout);
scanf("%d %d",&n,&m);
Build(root[0],1,n);
for(int i=1;i<=m;i++){
    int opt;
    scanf("%d",&opt);
    if(opt==1){
		int x,y,p,q;
		scanf("%d %d",&x,&y);
		x^=lastans;y^=lastans;
        root[i]=root[i-1];
        p=Find(root[i],x);
        q=Find(root[i],y);
        if(tree[p].v==tree[q].v)continue;
        if(deep[p]>deep[q])swap(p,q);
        Change(root[i-1],root[i],tree[p].v,tree[q].v);
        if(deep[p]==deep[q])Add(root[i],tree[q].v);
    }
    if(opt==2){
		int k;
		scanf("%d",&k);
		k^=lastans;
        root[i]=root[k];
    }
    if(opt==3){
		int x,y;
		scanf("%d %d",&x,&y);
		x^=lastans;y^=lastans;
		root[i]=root[i-1];
        if(tree[Find(root[i],x)].v==tree[Find(root[i],y)].v){puts("1");lastans=1;}
        else {puts("0");lastans=0;}
	}
}
return 0;
}

Splay模版题

调试两天总算A啦！

2016/2/21 *1

2016/3/20 *1

#include<cstdio>
#include<algorithm>
using namespace std;

int n,a[1000005],m;

struct Node{
int v,mx,sum,lx,rx,siz,tag,rev;
Node *ch[2],*fa;
Node(int val,Node *fat);
void Pushdown();
void Pushup();
}*root,*Null;

Node::Node(int val=0,Node *fat=Null){
ch[0]=ch[1]=Null;
fa=fat;
v=sum=mx=val;
tag=rev=0;
siz=1;
if(v>=0)lx=rx=v;
else lx=rx=0;
}

void Node::Pushdown(){
if(tag){
	tag=rev=0;
	if(ch[0]!=Null){ch[0]->tag=1;ch[0]->sum=ch[0]->siz*v;ch[0]->v=v;}
	if(ch[1]!=Null){ch[1]->tag=1;ch[1]->sum=ch[1]->siz*v;ch[1]->v=v;}
	if(v>=0){
        if(ch[0]!=Null){ch[0]->lx=ch[0]->mx=ch[0]->rx=v*ch[0]->siz;}
        if(ch[1]!=Null){ch[1]->lx=ch[1]->mx=ch[1]->rx=v*ch[1]->siz;}
	}
	else {
		if(ch[0]!=Null){ch[0]->mx=v;ch[0]->lx=ch[0]->rx=0;}
        if(ch[1]!=Null){ch[1]->mx=v;ch[1]->lx=ch[1]->rx=0;}
	}
}
if(rev){
	rev=0;
	if(ch[0]!=Null)ch[0]->rev^=1;
	if(ch[1]!=Null)ch[1]->rev^=1;
	swap(ch[0]->ch[0],ch[0]->ch[1]);
	swap(ch[1]->ch[0],ch[1]->ch[1]);
	swap(ch[0]->lx,ch[0]->rx);
	swap(ch[1]->lx,ch[1]->rx);
}
}

void Node::Pushup(){
siz=ch[0]->siz+ch[1]->siz+1;
sum=ch[0]->sum+ch[1]->sum+v;
mx=max(ch[0]->mx,ch[1]->mx);
mx=max(mx,ch[0]->rx+v+ch[1]->lx);
lx=max(ch[0]->lx,ch[0]->sum+v+ch[1]->lx);
rx=max(ch[1]->rx,ch[1]->sum+v+ch[0]->rx);
}

void Rotate(Node *x,int kind){
Node *y=x->fa,*z=y->fa;
y->ch[!kind]=x->ch[kind];
if(x->ch[kind]!=Null)x->ch[kind]->fa=y;
x->fa=z;
if(z!=Null)z->ch[z->ch[1]==y]=x;
y->fa=x;
x->ch[kind]=y;
y->Pushup();
x->Pushup();
}

void Splay(Node *x,Node *place){
while(x->fa!=place){
	Node *y=x->fa,*z=y->fa;
	if(z==Null || z==place)Rotate(x,y->ch[0]==x);
	else {
		if(y->ch[0]==x && z->ch[0]==y){Rotate(y,1);Rotate(x,1);}
		else if(y->ch[0]==x && z->ch[1]==y){Rotate(x,1);Rotate(x,0);}
		else if(y->ch[1]==x && z->ch[0]==y){Rotate(x,0);Rotate(x,1);}
		else {Rotate(y,0);Rotate(x,0);}
	}
}
if(place==Null)root=x;
}

Node *Find(Node *splay,int k){
splay->Pushdown();
if(splay->ch[0]->siz+1==k)return splay;
if(splay->ch[0]->siz>=k)return Find(splay->ch[0],k);
return Find(splay->ch[1],k-1-splay->ch[0]->siz);
}

Node *Split(int pos,int tot){
Node *x=Find(root,pos);
Splay(x,Null);
Node *y=Find(root,pos+tot+1);
Splay(y,root);
return y->ch[0];
}

Node *Build(int l,int r){
if(l>r)return Null;
int mid=l+r>>1;
Node *splay=new Node(a[mid],Null);
splay->ch[0]=Build(l,mid-1);
if(splay->ch[0]!=Null)splay->ch[0]->fa=splay;
splay->ch[1]=Build(mid+1,r);
if(splay->ch[1]!=Null)splay->ch[1]->fa=splay;
splay->Pushup();
return splay;
}

void Insert(int pos,int tot){
Node *x=Find(root,pos+1),*y=Find(root,pos+2);
Splay(x,Null);Splay(y,root);
y->ch[0]=Build(1,tot);
if(y->ch[0]!=Null)y->ch[0]->fa=y;
y->Pushup();
x->Pushup();
}

Node *GetNull(){
Node *p=new Node(0,Null);
p->fa=p->ch[0]=p->ch[1]=p;
p->mx=p->v=-1000000000;
p->rev=p->tag=p->siz=p->sum=p->lx=p->rx=0;
return p;
}

void Build_First(){
Null=GetNull();
a[1]=-1000000000;
a[n+2]=-1000000000;
root=Build(1,n+2);
}

void Del_Tree(Node *splay){
if(splay==Null)return;
splay->Pushdown();
Del_Tree(splay->ch[0]);
Del_Tree(splay->ch[1]);
if(splay->ch[0]!=Null)delete splay->ch[0];
if(splay->ch[1]!=Null)delete splay->ch[1];
splay->ch[0]=Null;
splay->ch[1]=Null;
splay->Pushup();
}

void Delete(int pos,int val){
Node *seq=Split(pos,val),*fat=seq->fa;
Del_Tree(seq);
if(seq!=Null)delete seq;
fat->ch[0]=Null;
fat->Pushup();
fat->fa->Pushup();
}

void MakeSame(int pos,int tot,int val){
Node *seq=Split(pos,tot),*fat=seq->fa;
seq->tag=1;
seq->sum=seq->siz*val;
seq->v=val;
if(val>=0)seq->lx=seq->rx=seq->mx=seq->siz*val;
else seq->lx=seq->rx=0,seq->mx=val;
fat->Pushup();
fat->fa->Pushup();
}

void Reverse(int pos,int tot){
Node *seq=Split(pos,tot),*fat=seq->fa;
if(!seq->tag){
	seq->rev^=1;
	swap(seq->ch[0],seq->ch[1]);
	swap(seq->lx,seq->rx);
	fat->Pushup();
	fat->fa->Pushup();
}
}

int GetSum(int pos,int tot){
Node *seq=Split(pos,tot);
return seq->sum;
}

int main(){
freopen("1500.in","r",stdin);
freopen("1500.out","w",stdout);
scanf("%d %d",&n,&m);
for(int i=2;i<=n+1;i++)scanf("%d",&a[i]);
Build_First();
for(int i=1;i<=m;i++){
	char s[10];
    scanf("%s",s);
    if(s[0]=='I'){
		int pos,tot;
		scanf("%d %d",&pos,&tot);
		for(int i=1;i<=tot;i++)scanf("%d",&a[i]);
		Insert(pos,tot);
	}
	if(s[0]=='D'){
		int pos,tot;
		scanf("%d %d",&pos,&tot);
		Delete(pos,tot);
	}
	if(s[0]=='M' && s[2]=='K'){
		int pos,tot,val;
		scanf("%d %d %d",&pos,&tot,&val);
        MakeSame(pos,tot,val);
	}
	if(s[0]=='M' && s[2]=='X'){
		printf("%d\n",root->mx);
	}
	if(s[0]=='R'){
		int pos,tot;
		scanf("%d %d",&pos,&tot);
		Reverse(pos,tot);
	}
	if(s[0]=='G'){
		int pos,tot;
		scanf("%d %d",&pos,&tot);
		printf("%d\n",GetSum(pos,tot));
	}
}
return 0;
}

嗯……这些ID都是我的

Lvat2000

Lvat_s

A_Star

Lvat_Violet

DreamPublisher

SkyChecker

OI_Endless

SnowSword

Initialize

好像就这些了……也许我自己忘了一些ID……