bzoj1500

原谅我一时没有打着道题的勇气。。。

#include<queue>#include<cmath>#include<cstdio>#include<cstring>#include<cstdlib>#include<iostream>#include<algorithm>#define inf 1000000000#define N 1000005using namespace std;int read(){int x=0,f=1;char ch=getchar();while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}return x*f;}//////////////////////////////////////////////////////int n,m,rt,cnt;int a[N],id[N],fa[N],c[N][2];int sum[N],size[N],v[N],mx[N],lx[N],rx[N];bool tag[N],rev[N];queue<int> q;void update(int x){int l=c[x][0],r=c[x][1];sum[x]=sum[l]+sum[r]+v[x];size[x]=size[l]+size[r]+1;mx[x]=max(mx[l],mx[r]);mx[x]=max(mx[x],rx[l]+v[x]+lx[r]);lx[x]=max(lx[l],sum[l]+v[x]+lx[r]);rx[x]=max(rx[r],sum[r]+v[x]+rx[l]);}void pushdown(int x){int l=c[x][0],r=c[x][1];if(tag[x]){rev[x]=tag[x]=0;if(l)tag[l]=1,v[l]=v[x],sum[l]=v[x]*size[l];if(r)tag[r]=1,v[r]=v[x],sum[r]=v[x]*size[r];if(v[x]>=0){if(l)lx[l]=rx[l]=mx[l]=sum[l];if(r)lx[r]=rx[r]=mx[r]=sum[r];}else {if(l)lx[l]=rx[l]=0,mx[l]=v[x];if(r)lx[r]=rx[r]=0,mx[r]=v[x];}}if(rev[x]){rev[x]^=1;rev[l]^=1;rev[r]^=1;swap(lx[l],rx[l]);swap(lx[r],rx[r]);swap(c[l][0],c[l][1]);swap(c[r][0],c[r][1]);}}void rotate(int x,int &k){int y=fa[x],z=fa[y],l,r;l=(c[y][1]==x);r=l^1;if(y==k)k=x;else c[z][c[z][1]==y]=x;fa[c[x][r]]=y;fa[y]=x;fa[x]=z;c[y][l]=c[x][r];c[x][r]=y;update(y);update(x);}void splay(int x,int &k){while(x!=k){int y=fa[x],z=fa[y];    if(y!=k){if(c[y][0]==x^c[z][0]==y)rotate(x,k);else rotate(y,k);}rotate(x,k);}}int find(int x,int rk){pushdown(x);int l=c[x][0],r=c[x][1];if(size[l]+1==rk)return x;if(size[l]>=rk)return find(l,rk);return find(r,rk-size[l]-1);}int split(int k,int tot){int x=find(rt,k),y=find(rt,k+tot+1);splay(x,rt);splay(y,c[x][1]);return c[y][0];}void modify(int k,int tot,int val){int x=split(k,tot),y=fa[x];v[x]=val;tag[x]=1;sum[x]=size[x]*val;if(val>=0)lx[x]=rx[x]=mx[x]=sum[x];else lx[x]=rx[x]=0,mx[x]=val;update(y);update(fa[y]);}void rever(int k,int tot){int x=split(k,tot),y=fa[x];if(!tag[x]){rev[x]^=1;swap(c[x][0],c[x][1]);swap(lx[x],rx[x]);update(y);update(fa[y]);}}void query(int k,int tot){int x=split(k,tot);printf("%d\n",sum[x]);}void rec(int x){if(!x)return;int l=c[x][0],r=c[x][1];rec(l);rec(r);q.push(x);fa[x]=c[x][0]=c[x][1]=0;tag[x]=rev[x]=0;}void erase(int k,int tot){int x=split(k,tot),y=fa[x];rec(x);c[y][0]=0;update(y);update(fa[y]);}void build(int l,int r,int f){if(l>r)return;int mid=(l+r)>>1,now=id[mid],last=id[f];if(l==r){sum[now]=a[l];size[now]=1;tag[now]=rev[now]=0;if(a[l]>=0)lx[now]=rx[now]=mx[now]=a[l];else lx[now]=rx[now]=0,mx[now]=a[l];}else build(l,mid-1,mid),build(mid+1,r,mid);v[now]=a[mid];fa[now]=last;update(now);c[last][mid>=f]=now;   }void insert(int k,int tot){for(int i=1;i<=tot;i++)a[i]=read();for(int i=1;i<=tot;i++)if(!q.empty())id[i]=q.front(),q.pop();else id[i]=++cnt;build(1,tot,0);int z=id[(1+tot)>>1];int x=find(rt,k+1),y=find(rt,k+2);splay(x,rt);splay(y,c[x][1]);fa[z]=y;c[y][0]=z;update(y);update(x);}int main(){n=read();m=read();mx[0]=a[1]=a[n+2]=-inf;for(int i=1;i<=n;i++)a[i+1]=read();for(int i=1;i<=n+2;i++)id[i]=i;build(1,n+2,0);rt=(n+3)>>1;cnt=n+2;int k,tot,val;char ch[10];while(m--){scanf("%s",ch);if(ch[0]!='M'||ch[2]!='X')k=read(),tot=read();if(ch[0]=='I')insert(k,tot);if(ch[0]=='D')erase(k,tot);if(ch[0]=='M'){if(ch[2]=='X')printf("%d\n",mx[rt]);else val=read(),modify(k,tot,val);}if(ch[0]=='R')rever(k,tot);if(ch[0]=='G')query(k,tot);}return 0;}