BZOJ 2209: [Jsoi2011]括号序列&&BZOJ 2329: [HNOI2011]括号修复

双倍经验题好评

画了一下午括号没想出来QAQ简直蠢哭了

把左括号看成1，右括号看成-1，答案就是（最小前缀和的绝对值+1）/2+（最大后缀和+1）/2

然后因为有三个操作所以还要顺便维护下最大前缀和&&最小后缀和

BTW HNOI的那道题暴力比我的splay跑得快QAQ

为什么我的splay感觉就是在地上爬啊

2209：

#include<iostream>
#include<cstdio>
#include<cstring>
using namespace std;
const int N=100000+5;
int fa[N],ch[N][2],sz[N],lmx[N],rmx[N],lmi[N],rmi[N],v[N],sum[N],root;
int inv[N],rev[N];
#define lc(x) ch[x][0]
#define rc(x) ch[x][1]
void pushup(int x){
    sz[x]=sz[lc(x)]+sz[rc(x)]+1;
    sum[x]=sum[lc(x)]+sum[rc(x)]+v[x];
    lmx[x]=max(lmx[lc(x)],sum[lc(x)]+lmx[rc(x)]+v[x]);
    rmx[x]=max(rmx[rc(x)],sum[rc(x)]+rmx[lc(x)]+v[x]);
    lmi[x]=min(lmi[lc(x)],sum[lc(x)]+lmi[rc(x)]+v[x]);
    rmi[x]=min(rmi[rc(x)],sum[rc(x)]+rmi[lc(x)]+v[x]);
}
void makeinv(int x){
    inv[x]^=1;
    swap(lmx[x],lmi[x]);lmx[x]*=-1;lmi[x]*=-1;
    swap(rmx[x],rmi[x]);rmx[x]*=-1;rmi[x]*=-1;
    v[x]*=-1;sum[x]*=-1;
}
void makerev(int x){
    rev[x]^=1;
    swap(lmx[x],rmx[x]);swap(lmi[x],rmi[x]);
    swap(lc(x),rc(x));
}
void pushdown(int x){
    if(inv[x]){
        makeinv(lc(x));makeinv(rc(x));
        inv[x]=0;
    }
    if(rev[x]){
        makerev(lc(x));makerev(rc(x));
        rev[x]=0;
    }
}
void rotate(int x,int &k){
    int y=fa[x],z=fa[y],l=ch[y][1]==x,r=l^1;
    if(y==k)k=x;
    else ch[z][ch[z][1]==y]=x;
    fa[x]=z;fa[y]=x;fa[ch[x][r]]=y;
    ch[y][l]=ch[x][r];ch[x][r]=y;
    pushup(y);pushup(x);
}
void splay(int x,int &k){
    while(x!=k){
        int y=fa[x],z=fa[y];
        if(y!=k){
            if(ch[z][0]==y^ch[y][0]==x)rotate(x,k);
            else rotate(y,k);
        }
        rotate(x,k);
    }
}
int kth(int x,int k){
    pushdown(x);
    int r=sz[lc(x)]+1;
    if(k==r)return x;
    else if(k<r)return kth(lc(x),k);
    else return kth(rc(x),k-r);
}
int split(int a,int b){
    int x=kth(root,a),y=kth(root,b+2);
    splay(x,root);splay(y,ch[x][1]);
    return ch[y][0];
}
void invert(int a,int b){
    int x=split(a,b);
    makeinv(x);
}
void rever(int a,int b){
    int x=split(a,b);
    makerev(x);
}
int abs(int x){
    return x>0?x:-x;
}
int query(int a,int b){
    int x=split(a,b);
    return (abs(lmi[x])+1>>1)+(rmx[x]+1>>1);
}
int build(int l,int r){
    if(l>r)return 0;
    if(l==r){
        lmi[l]=rmi[l]=min(0,v[l]);
        lmx[l]=rmx[l]=max(0,v[l]);
        sz[l]=1;sum[l]=v[l];
        return l;
    }else{
        int mid=l+r>>1;
        lc(mid)=build(l,mid-1);rc(mid)=build(mid+1,r);
        fa[lc(mid)]=fa[rc(mid)]=mid;
        pushup(mid);
        return mid;
    }
}
char s[N];
int main(){
    //freopen("a.in","r",stdin);
    //freopen("a.out","w",stdout);
    int n,m;scanf("%d%d",&n,&m);
    scanf("%s",s+2);
    for(int i=1;i<=n+2;i++)
    if(s[i]=='(')v[i]=1;
    else if(s[i]==')')v[i]=-1;
    root=build(1,n+2);
    int opt,a,b;
    while(m--){
        scanf("%d%d%d",&opt,&a,&b);
        if(opt==0)printf("%d\n",query(a,b));
        else if(opt==1)invert(a,b);
        else rever(a,b);
    }
    return 0;
}

2329：

#include<iostream>
#include<cstdio>
#include<cstring>
using namespace std;
const int N=100000+5;
int fa[N],ch[N][2],sz[N],lmx[N],rmx[N],lmi[N],rmi[N],v[N],sum[N],root;
int inv[N],rev[N],set[N];
#define lc(x) ch[x][0]
#define rc(x) ch[x][1]
void pushup(int x){
    sz[x]=sz[lc(x)]+sz[rc(x)]+1;
    sum[x]=sum[lc(x)]+sum[rc(x)]+v[x];
    lmx[x]=max(lmx[lc(x)],sum[lc(x)]+lmx[rc(x)]+v[x]);
    rmx[x]=max(rmx[rc(x)],sum[rc(x)]+rmx[lc(x)]+v[x]);
    lmi[x]=min(lmi[lc(x)],sum[lc(x)]+lmi[rc(x)]+v[x]);
    rmi[x]=min(rmi[rc(x)],sum[rc(x)]+rmi[lc(x)]+v[x]);
}
void makeinv(int x){
    inv[x]^=1;
    swap(lmx[x],lmi[x]);lmx[x]*=-1;lmi[x]*=-1;
    swap(rmx[x],rmi[x]);rmx[x]*=-1;rmi[x]*=-1;
    v[x]*=-1;sum[x]*=-1;
}
void makerev(int x){
    rev[x]^=1;
    swap(lmx[x],rmx[x]);swap(lmi[x],rmi[x]);
    swap(lc(x),rc(x));
}
void makeset(int x,int flag){
    inv[x]=rev[x]=0;
    set[x]=flag;
    sum[x]=flag*sz[x];
    lmx[x]=rmx[x]=max(0,sum[x]);
    lmi[x]=rmi[x]=min(0,sum[x]);
    v[x]=flag;
}
void pushdown(int x){
    if(set[x]){
        makeset(lc(x),set[x]);makeset(rc(x),set[x]);
        set[x]=0;
    }
    if(inv[x]){
        makeinv(lc(x));makeinv(rc(x));
        inv[x]=0;
    }
    if(rev[x]){
        makerev(lc(x));makerev(rc(x));
        rev[x]=0;
    }
}
void rotate(int x,int &k){
    int y=fa[x],z=fa[y],l=ch[y][1]==x,r=l^1;
    if(y==k)k=x;
    else ch[z][ch[z][1]==y]=x;
    fa[x]=z;fa[y]=x;fa[ch[x][r]]=y;
    ch[y][l]=ch[x][r];ch[x][r]=y;
    pushup(y);pushup(x);
}
void splay(int x,int &k){
    while(x!=k){
        int y=fa[x],z=fa[y];
        if(y!=k){
            if(ch[z][0]==y^ch[y][0]==x)rotate(x,k);
            else rotate(y,k);
        }
        rotate(x,k);
    }
}
int kth(int x,int k){
    pushdown(x);
    int r=sz[lc(x)]+1;
    if(k==r)return x;
    else if(k<r)return kth(lc(x),k);
    else return kth(rc(x),k-r);
}
int split(int a,int b){
    int x=kth(root,a),y=kth(root,b+2);
    splay(x,root);splay(y,ch[x][1]);
    return ch[y][0];
}
void invert(int a,int b){
    int x=split(a,b);
    makeinv(x);
}
void rever(int a,int b){
    int x=split(a,b);
    makerev(x);
}
void replace(int a,int b,int c){
    int x=split(a,b);
    makeset(x,c);
}
int abs(int x){
    return x>0?x:-x;
}
int query(int a,int b){
    int x=split(a,b);
    return (abs(lmi[x])+1>>1)+(rmx[x]+1>>1);
}
int build(int l,int r){
    if(l>r)return 0;
    if(l==r){
        lmi[l]=rmi[l]=min(0,v[l]);
        lmx[l]=rmx[l]=max(0,v[l]);
        sz[l]=1;sum[l]=v[l];
        return l;
    }else{
        int mid=l+r>>1;
        lc(mid)=build(l,mid-1);rc(mid)=build(mid+1,r);
        fa[lc(mid)]=fa[rc(mid)]=mid;
        pushup(mid);
        return mid;
    }
}
char s[N];
int main(){
    //freopen("a.in","r",stdin);
    //freopen("a.out","w",stdout);
    int n,m;scanf("%d%d",&n,&m);
    scanf("%s",s+2);
    for(int i=1;i<=n+2;i++)
    if(s[i]=='(')v[i]=1;
    else if(s[i]==')')v[i]=-1;
    root=build(1,n+2);
    char opt[10],c[5];
    int a,b;
    while(m--){
        scanf("%s%d%d",opt,&a,&b);
        if(opt[0]=='Q')printf("%d\n",query(a,b));
        else if(opt[0]=='I')invert(a,b);
        else if(opt[0]=='S')rever(a,b);
        else{
            scanf("%s",c);
            replace(a,b,c[0]=='('?1:-1);
        }
    }
    return 0;
}