BZOJ2329: [HNOI2011]括号修复

  1 #include<cstdio>
  2 #include<cstdlib>
  3 #include<cmath>
  4 #include<cstring>
  5 #include<algorithm>
  6 #include<iostream>
  7 #include<vector>
  8 #include<map>
  9 #include<set>
 10 #include<queue>
 11 #include<string>
 12 #define inf 1000000000
 13 #define maxn 150000+5
 14 #define maxm 500+100
 15 #define eps 1e-10
 16 #define ll long long
 17 #define pa pair<int,int>
 18 #define for0(i,n) for(int i=0;i<=(n);i++)
 19 #define for1(i,n) for(int i=1;i<=(n);i++)
 20 #define for2(i,x,y) for(int i=(x);i<=(y);i++)
 21 #define for3(i,x,y) for(int i=(x);i>=(y);i--)
 22 #define mod 1000000007
 23 using namespace std;
 24 inline int read()
 25 {
 26     int x=0,f=1;char ch=getchar();
 27     while(ch<‘0‘||ch>‘9‘){if(ch==‘-‘)f=-1;ch=getchar();}
 28     while(ch>=‘0‘&&ch<=‘9‘){x=10*x+ch-‘0‘;ch=getchar();}
 29     return x*f;
 30 }
 31 int n,m,c[maxn][2],fa[maxn],li[maxn],ri[maxn],lx[maxn],rx[maxn],sum[maxn],s[maxn],v[maxn];
 32 int rt,t1,t2;
 33 bool cov[maxn],rev[maxn],inv[maxn];
 34 inline void pushup(int x)
 35 {
 36     int l=c[x][0],r=c[x][1];
 37     s[x]=s[l]+s[r]+1;
 38     sum[x]=sum[l]+sum[r]+v[x];
 39     lx[x]=max(lx[l],sum[l]+v[x]+max(0,max(lx[r],sum[r])));
 40     rx[x]=max(rx[r],sum[r]+v[x]+max(0,max(rx[l],sum[l])));
 41     li[x]=min(li[l],sum[l]+v[x]+min(0,min(li[r],sum[r])));
 42     ri[x]=min(ri[r],sum[r]+v[x]+min(0,min(ri[l],sum[l])));
 43 }
 44 inline void rotate(int x,int &k)
 45 {
 46     int y=fa[x],z=fa[y],l=c[y][1]==x,r=l^1;
 47     if(y!=k)c[z][c[z][1]==y]=x;else k=x;
 48     fa[x]=z;fa[y]=x;fa[c[x][r]]=y;
 49     c[y][l]=c[x][r];c[x][r]=y;
 50     pushup(y);pushup(x);
 51 }
 52 inline void splay(int x,int &k)
 53 {
 54     while(x!=k)
 55     {
 56         int y=fa[x],z=fa[y];
 57         if(y!=k)
 58         {
 59             if(c[z][0]==y^c[y][0]==x)rotate(x,k);else rotate(y,k);
 60         }
 61         rotate(x,k);
 62     }
 63 }
 64 inline void cover(int x,int y)
 65 {
 66     cov[x]=1;v[x]=y;rev[x]=inv[x]=0;
 67     sum[x]=s[x]*y;
 68     lx[x]=rx[x]=y>0?sum[x]:0;
 69     li[x]=ri[x]=y>0?0:sum[x];
 70 }
 71 inline void rever(int x)
 72 {
 73     if(cov[x])return;
 74     rev[x]^=1;
 75     swap(c[x][0],c[x][1]);
 76     swap(lx[x],rx[x]);
 77     swap(li[x],ri[x]);
 78 }
 79 inline void invert(int x)
 80 {
 81     inv[x]^=1;v[x]=-v[x];
 82     swap(li[x],lx[x]);li[x]=-li[x];lx[x]=-lx[x];
 83     swap(ri[x],rx[x]);ri[x]=-ri[x];rx[x]=-rx[x];
 84     sum[x]=-sum[x];
 85     if(cov[x])inv[x]=0;
 86 }
 87 inline void pushdown(int x)
 88 {
 89     if(cov[x]){cover(c[x][0],v[x]);cover(c[x][1],v[x]);cov[x]=0;}
 90     if(rev[x]){rever(c[x][0]);rever(c[x][1]);rev[x]=0;}
 91     if(inv[x]){invert(c[x][0]);invert(c[x][1]);inv[x]=0;}
 92 }
 93 inline int find(int x,int k)
 94 {
 95     pushdown(x);
 96     int l=c[x][0],r=c[x][1];
 97     if(s[l]+1==k)return x;
 98     else if(s[l]>=k)return find(l,k);
 99     else return find(r,k-s[l]-1);
100 }
101 inline void split(int l,int r)
102 {
103     t1=find(rt,l);t2=find(rt,r);
104     splay(t1,rt);splay(t2,c[t1][1]);
105 }
106 inline void build(int l,int r,int f)
107 {
108     if(l>r)return;
109     int x=(l+r)>>1;
110     fa[x]=f;c[f][x>f]=x;
111     if(l==r){s[x]=1;li[x]=ri[x]=v[x]>0?0:v[x];lx[x]=rx[x]=v[x]>0?v[x]:0;sum[x]=v[x];return;}
112     build(l,x-1,x);build(x+1,r,x);
113     pushup(x);
114 }
115 int main()
116 {
117     freopen("input.txt","r",stdin);
118     freopen("output.txt","w",stdout);
119     n=read();m=read();
120     v[1]=v[n+2]=0;
121     for2(i,2,n+1){char ch=getchar();while(ch!=‘(‘&&ch!=‘)‘)ch=getchar();v[i]=ch==‘(‘?1:-1;}
122     build(1,n+2,0);rt=(1+n+2)>>1;
123     while(m--)
124     {
125         int ch=read();int x=read(),y=read();split(x,y+2);int z=c[t2][0];
126         if(!ch)printf("%d\n",(-li[z]+1)/2+(rx[z]+1)/2);
127         else if(ch==1)invert(z);else rever(z);
128         pushup(t2);pushup(t1);
129     }
130     return 0;
131 }