noi 2005维修数列

  1 #include<cstdio>
  2 #include<cstring>
  3 #include<iostream>
  4 #include<algorithm>
  5 #include<queue>
  6 #define inc(i,l,r) for(i=l;i<=r;i++)
  7 #define dec(i,l,r) for(i=l;i>=r;i--)
  8 #define inf 1e9
  9 #define mem(a) memset(a,0,sizeof(a))
 10 #define ll long long
 11 #define NM 1000000+5
 12 using namespace std;
 13 int read(){
 14     int x=0,f=1;char ch=getchar();
 15     while(!isdigit(ch)){if(ch==‘-‘)f=-1;ch=getchar();}
 16     while(isdigit(ch))x=x*10+ch-‘0‘,ch=getchar();
 17     return x*f;
 18 }
 19 int n,m,i,x,t,w[NM];
 20     int root,tot,c[NM][2],f[NM],a[NM],b[NM],L[NM],R[NM],M[NM],val[NM],s[NM],z[NM];
 21     bool v[NM];
 22     queue<int>q;
 23     void newnode(int &r,int fa,int k){
 24         if(!q.empty())r=q.front(),q.pop();else r=++tot;
 25         f[r]=fa;c[r][0]=c[r][1]=0;
 26         b[r]=1;
 27         s[r]=a[r]=M[r]=k;
 28         if(k>0)L[r]=R[r]=k;else L[r]=R[r]=0;
 29         val[r]=v[r]=z[r]=0;
 30     }
 31     void rev(int x){
 32         swap(c[x][0],c[x][1]);swap(L[x],R[x]);z[x]^=1;
 33     }
 34     void ch(int x,int k){
 35         val[x]=a[x]=k;v[x]=1;s[x]=b[x]*val[x];
 36         if(val[x]>0)
 37         L[x]=R[x]=M[x]=s[x];
 38         else L[x]=R[x]=0,M[x]=val[x];
 39     }
 40     void update(int r){
 41         int x=c[r][0],y=c[r][1];
 42         if(x==0)x=tot+1,M[x]=-inf;
 43         if(y==0)y=tot+1,M[y]=-inf;
 44         b[r]=b[x]+b[y]+1;
 45         s[r]=s[x]+s[y]+a[r];
 46         L[r]=max(L[x],s[x]+L[y]+a[r]);
 47         R[r]=max(R[y],R[x]+s[y]+a[r]);
 48         M[r]=max(M[x],M[y]);
 49         M[r]=max(M[r],R[x]+a[r]+L[y]);
 50     }
 51     void pushdown(int x){
 52         if(v[x]){
 53             ch(c[x][0],val[x]);ch(c[x][1],val[x]);
 54             v[x]=0;z[x]=0;
 55         }
 56         if(z[x]){
 57             rev(c[x][0]);rev(c[x][1]);
 58             z[x]=0;
 59         }
 60     }
 61     int d(int x){
 62         return c[f[x]][1]==x;
 63     }
 64     void rot(int x){
 65         int y=f[x],kind=!d(x);
 66         pushdown(c[x][kind]);
 67         c[y][!kind]=c[x][kind];
 68         f[c[x][kind]]=y;
 69         if(f[y])c[f[y]][d(y)]=x;
 70         f[x]=f[y];
 71         c[x][kind]=y;
 72         f[y]=x;
 73         update(y);
 74         update(x);
 75     }
 76     void splay(int x,int goal=0){
 77         for(int y=f[x];y!=goal;y=f[x]){
 78             pushdown(y);pushdown(x);
 79             if(f[y]!=goal)
 80             d(y)==d(x)?rot(y):rot(x);
 81             rot(x);
 82         }
 83         if(goal==0)root=x;
 84     }
 85     int sel(int x){
 86         int r=root;
 87         while(x>0){
 88             pushdown(r);
 89             int t=b[c[r][0]];
 90             if(x==t+1)return r;
 91             if(x>t){
 92                 x-=t+1;r=c[r][1];
 93             }else r=c[r][0];
 94         }
 95     }
 96     int pick(int x,int y){
 97         x++;y++;
 98         y=sel(y);x=sel(x);
 99         splay(x);splay(y,x);
100         return y;
101     }
102     void rec(int x){
103         q.push(x);
104         if(c[x][0])rec(c[x][0]);
105         if(c[x][1])rec(c[x][1]);
106     }
107     void del(int x,int t){
108         x=pick(x-1,x+t);
109         rec(c[x][0]);
110         f[c[x][0]]=0;c[x][0]=0;
111         update(x);
112         splay(x);
113     }
114     int sum(int x,int t){
115         x=pick(x-1,x+t);
116         return s[c[x][0]];
117     }
118     int link(){
119         int r=root;
120         pushdown(c[r][0]);pushdown(c[r][1]);
121         update(r);
122         return M[r];
123     }
124     void build(int x,int y,int fa,int &r){
125         int t=x+y>>1;
126         if(x>y)return;
127         newnode(r,fa,w[t]);
128         build(x,t-1,r,c[r][0]);
129         build(t+1,y,r,c[r][1]);
130         update(r);
131     }
132     void ins(int x,int t){
133         int i;
134         x=pick(x,x+1);
135         inc(i,1,t)w[i]=read();
136         build(1,t,x,c[x][0]);
137         update(x);
138         splay(c[x][0]);
139     }
140 int main(){
141 //    freopen("sequence.in","r",stdin);
142 //    freopen("sequence.ans","w",stdout);
143     n=read();m=read();
144     newnode(root,0,-inf);newnode(c[root][1],root,-inf);update(root);
145     ins(0,n);
146     inc(i,1,m){
147         char s=getchar();
148         while(s<‘A‘||s>‘Z‘)s=getchar();
149         s=getchar();s=getchar();
150         if(s==‘X‘){
151         printf("%d\n",link());
152         while((‘A‘<=s&&s<=‘Z‘)||s==‘-‘)s=getchar();
153         }
154         else{
155             getchar();getchar();
156             x=read();t=read();
157             if(s==‘L‘)del(x,t);
158             else if(s==‘T‘)printf("%d\n",sum(x,t));
159             else if(s==‘V‘){
160                 x=pick(x-1,x+t);
161                 x=c[x][0];
162                 if(v[x])continue;
163                 rev(x);
164                 pushdown(x);
165                 splay(x);
166             }
167             else if(s==‘K‘){
168                 x=pick(x-1,x+t);
169                 x=c[x][0];
170                 val[x]=read();v[x]=1;
171                 ch(x,val[x]);
172                 pushdown(x);
173                 splay(x);
174             }
175             else ins(x,t);
176         }
177     }
178     return 0;
179 }