1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136
| #include <bits/stdc++.h> #define MAXN 500005 using namespace std; inline 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; } namespace FHQ_Treap{ struct node{ int l,r; int val; int pri; int sz; int sum; int lmax,rmax; int maxn; }tree[MAXN]; int tot; #define lc(i) tree[i].l #define rc(i) tree[i].r inline void Update(int x){ tree[x].sz=tree[lc(x)].sz+tree[rc(x)].sz+1; tree[x].sum=tree[lc(x)].sum+tree[rc(x)].sum+tree[x].val; tree[x].lmax=max(tree[lc(x)].lmax,tree[lc(x)].sum+tree[x].val+tree[rc(x)].lmax); tree[x].rmax=max(tree[rc(x)].rmax,tree[lc(x)].rmax+tree[x].val+tree[rc(x)].sum); tree[x].maxn=max(max(tree[lc(x)].maxn,tree[rc(x)].maxn),tree[lc(x)].rmax+tree[x].val+tree[rc(x)].lmax); } inline int New(int v){ tree[++tot].val=v; tree[tot].pri=rand(); tree[tot].sz=1; tree[tot].maxn=tree[tot].sum=v; tree[tot].lmax=tree[tot].rmax=max(v,0); return tot; } int Merge(int x,int y){ if (!x||!y) return x+y; if (tree[x].pri<tree[y].pri){ rc(x)=Merge(rc(x),y),Update(x); return x; } else { lc(y)=Merge(x,lc(y)),Update(y); return y; } }
void Split(int i,int k,int &x,int &y){ if (!i) { x=y=0; } else { if (tree[lc(i)].sz>=k) {y=i,Split(lc(i),k,x,lc(i));} else {x=i,Split(rc(i),k-tree[lc(i)].sz-1,rc(i),y);} Update(i); } } int root,x,y,z; void Init(){ tot=0,root=0; memset(tree,0,sizeof(tree)); srand(19260817); } inline void Add(int pos,int num){ Split(root,pos,x,y); root=Merge(Merge(x,New(num)),y); } inline void Del(int pos){ Split(root,pos,x,z); Split(x,pos-1,x,y); y=Merge(lc(y),rc(y)); root=Merge(Merge(x,y),z); } }; using namespace FHQ_Treap; inline char gc(){ char ch=getchar(); while (ch!='I'&&ch!='D'&&ch!='R'&&ch!='Q') ch=getchar(); return ch; } int main(){ Init(); int n=read(); for (register int i=1;i<=n;++i){ int x=read(); root=Merge(root,New(x)); } tree[0].maxn=-0x7fffffff; int q=read(); while (q--){ char opr=gc(); if (opr=='I'){ int p=read(),x=read(); Add(p-1,x); } else if (opr=='D'){ int p=read(); Del(p); } else if (opr=='R'){ int p=read(),x=read(); Del(p),Add(p-1,x); } else { int l=read(),r=read(); Split(root,r,x,z); Split(x,l-1,x,y); printf("%d\n",tree[y].maxn); root=Merge(Merge(x,y),z); } } }
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