splay乱搞。
调了两个多小时。。。这辈子再也不想写splay了。。。
维护左边最大连续和右边最大连续，维护两个标记，无脑push_down、push_up就行了。
注意最大连续和至少要包含一个数。
1 #include<iostream> 2 #include<cstdio> 3 #include<cstring> 4 #include<algorithm> 5 #define N 500010 6 #define M 5000005 7 #define inf 0x3f3f3f3f 8 #define lc(x) ch[x][0] 9 #define rc(x) ch[x][1] 10 using namespace std; 11 int n,m; 12 int cnt; 13 int a[N],root,ch[N][2],tmproot; 14 int sum[N],ls[N],rs[N],mx[N],ji[N]; 15 int lazy[N],size[N],zhi[N],fa[N]; 16 int s[M],tot2; 17 inline int mxx(int x,int y) 18 { 19 if(x>y)return x;return y; 20 } 21 // ls 左边最大 rs 右边最大 22 void push_up(int x) 23 { 24 size[x]=size[lc(x)]+size[rc(x)]+1; 25 sum[x]=sum[lc(x)]+sum[rc(x)]+zhi[x]; 26 mx[x]=mxx(mx[lc(x)],mxx(mx[rc(x)],zhi[x]+rs[lc(x)]+ls[rc(x)])); 27 ls[x]=mxx(0,mxx(ls[lc(x)],sum[lc(x)]+zhi[x]+ls[rc(x)])); 28 rs[x]=mxx(0,mxx(rs[rc(x)],sum[rc(x)]+zhi[x]+rs[lc(x)])); 29 return ; 30 } 31 void push_down(int x) 32 { 33 int l=ch[x][0];int r=ch[x][1]; 34 if(ji[x]!=-1001) 35 { 36 ji[l]=ji[r]=ji[x]; 37 sum[l]=size[l]*ji[x];sum[r]=size[r]*ji[x]; 38 zhi[l]=zhi[r]=ji[x]; 39 if(ji[x]>0)ls[l]=rs[l]=mx[l]=sum[l],ls[r]=rs[r]=mx[r]=sum[r]; 40 else ls[l]=rs[l]=0,ls[r]=rs[r]=0,mx[l]=mx[r]=ji[x]; 41 ji[x]=-1001; 42 } 43 if(lazy[x]==1) 44 { 45 lazy[l]^=1;lazy[r]^=1; 46 swap(ch[l][0],ch[l][1]); 47 swap(ch[r][0],ch[r][1]); 48 swap(ls[l],rs[l]);swap(ls[r],rs[r]); 49 lazy[x]=0; 50 } 51 sum[0]=ls[0]=rs[0]=0;mx[0]=-inf; 52 return ; 53 } 54 void build(int x,int l,int r) 55 { 56 if(l==r) 57 { 58 size[x]=1; 59 sum[x]=zhi[x]=mx[x]=a[l]; 60 rs[x]=ls[x]=max(0,a[l]); 61 return ; 62 } 63 int mid=(l+r)>>1; 64 if(l!=mid) 65 { 66 if(tot2)ch[x][0]=s[tot2--]; 67 else ch[x][0]=++cnt; 68 fa[ch[x][0]]=x,build(ch[x][0],l,mid-1); 69 } 70 if(tot2)ch[x][1]=s[tot2--]; 71 else ch[x][1]=++cnt; 72 fa[ch[x][1]]=x,build(ch[x][1],mid+1,r); 73 zhi[x]=a[mid]; 74 push_up(x); 75 } 76 void rotate(int p) 77 { 78 int q=fa[p],y=fa[q],x=(ch[q][1]==p); 79 ch[q][x]=ch[p][x^1];fa[ch[q][x]]=q; 80 ch[p][x^1]=q;fa[q]=p; 81 fa[p]=y; 82 if(y) 83 { 84 if(ch[y][1]==q)ch[y][1]=p; 85 else ch[y][0]=p; 86 } 87 push_up(q); 88 return ; 89 } 90 void splay(int x,int yy) 91 { 92 for(int y;y=fa[x];rotate(x)) 93 { 94 if(y==yy)break; 95 if(fa[y]!=yy) 96 { 97 if((lc(fa[y])==y&&lc(y)==x)||(rc(fa[y])==y&&rc(y)==x))rotate(y); 98 else rotate(x); 99 } 100 } 101 push_up(x); 102 if(!yy)root=x; 103 } 104 int find(int k,int x) 105 { 106 push_down(k); 107 int l=lc(k),r=rc(k); 108 if(size[l]+1==x)return k; 109 if(size[l]+1>x)return find(l,x); 110 else return find(r,x-size[l]-1); 111 } 112 char c[20]; 113 void dfs(int x) 114 { 115 if(!x)return ; 116 cout<<zhi[x]<<' '<<sum[x]<<' '<<size[x]<<endl; 117 dfs(ch[x][0]);dfs(ch[x][1]); 118 } 119 void del(int x) 120 { 121 if(!x)return ; 122 s[++tot2]=x;ji[x]=-1001;lazy[x]=0;sum[x]=0; 123 del(ch[x][0]);del(ch[x][1]); 124 ch[x][0]=ch[x][1]=0;fa[x]=0;size[x]=0; 125 } 126 int main() 127 { 128 scanf("%d%d",&n,&m); 129 mx[0]=-inf; 130 for(int i=1;i<=n;i++)scanf("%d",&a[i]); 131 for(int i=1;i<N;i++)ji[i]=-1001; 132 root=++cnt; 133 a[0]=a[n+1]=0; 134 build(cnt,0,n+1); 135 int t1,t2,t3,t4,t5,t6; 136 for(int i=1;i<=m;i++) 137 { 138 scanf("%s",c); 139 if(c[0]=='I') 140 { 141 scanf("%d%d",&t1,&t2); 142 for(int j=1;j<=t2;j++)scanf("%d",&a[j]); 143 if(tot2)tmproot=s[tot2--]; 144 else tmproot=++cnt; 145 build(tmproot,1,t2); 146 t1++;t3=find(root,t1); 147 splay(t3,0); 148 t4=ch[t3][1];push_down(t4); 149 while(ch[t4][0])t4=ch[t4][0],push_down(t4); 150 splay(t4,t3);ch[t4][0]=tmproot;fa[tmproot]=t4;push_up(t4);push_up(t3); 151 } 152 else if(c[0]=='D') 153 { 154 scanf("%d%d",&t1,&t2); 155 t3=find(root,t1); 156 splay(t3,0); 157 t2=t2+t1+1; 158 t4=find(root,t2); 159 splay(t4,t3); 160 del(ch[t4][0]); 161 ch[t4][0]=0; 162 push_up(t4);push_up(t3); 163 } 164 else if(c[0]=='R') 165 { 166 scanf("%d%d",&t1,&t2); 167 t3=find(root,t1);splay(t3,0);t2=t2+t1+1;t4=find(root,t2); 168 splay(t4,t3); 169 t5=ch[t4][0]; 170 lazy[t5]^=1;swap(ch[t5][0],ch[t5][1]);swap(ls[t5],rs[t5]); 171 push_up(t4);push_up(t3); 172 } 173 else if(c[0]=='G') 174 { 175 scanf("%d%d",&t1,&t2); 176 t3=find(root,t1); 177 splay(t3,0);t2=t2+t1+1; 178 t4=find(root,t2); 179 splay(t4,t3); 180 printf("%d ",sum[ch[t4][0]]); 181 } 182 else if(c[0]=='M'&&c[4]=='S') 183 { 184 t1=find(root,1); 185 splay(t1,0); 186 t2=find(root,size[root]); 187 splay(t2,t1); 188 printf("%d ",mx[ch[t2][0]]); 189 } 190 else 191 { 192 scanf("%d%d%d",&t1,&t2,&t6); 193 t3=find(root,t1);splay(t3,0);t2=t2+t1+1; 194 t4=find(root,t2); 195 splay(t4,t3); 196 t5=ch[t4][0]; 197 ji[t5]=t6;zhi[t5]=t6;sum[t5]=size[t5]*t6; 198 if(t6>0)ls[t5]=rs[t5]=mx[t5]=sum[t5]; 199 else ls[t5]=rs[t5]=0,mx[t5]=t6; 200 push_up(t4);push_up(t3); 201 } 202 } 203 return 0; 204 }