题目链接:http://www.lydsy.com/JudgeOnline/problem.php?id=4196
一眼链剖
果断去找以前打的板子,顺便又复习了一遍
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#include<bits/stdc++.h> #define MAXN 100010 #define inf 999999999 using namespace std; inline int rd(){ int x=0,y=1;char c=getchar(); while(c<'0' || c>'9'){if(c=='-')y=-y;c=getchar();} while(c>='0'&&c<='9')x=x*10+c-'0',c=getchar(); return x*y; } struct node{ int sum; int l,r,len; int lazy; }tree[MAXN*4]; int n; int w[MAXN],son[MAXN],totree[MAXN],pre[MAXN],deep[MAXN],fa[MAXN],num[MAXN],top[MAXN]; int tot=1; vector<int>v[MAXN]; void link(int x,int y){ v[x].push_back(y); v[y].push_back(x); } void dfs1(int x,int d){ deep[x]=d; num[x]=1; for(int i=0; i<v[x].size(); i++){ int to=v[x][i]; if(to==fa[x])continue; fa[to]=x; dfs1(to,d+1); num[x]+=num[to]; if(!son[x] || num[to]>num[son[x]])son[x]=to; } } void dfs2(int x,int y){ top[x]=y; totree[x]=tot; pre[tot]=x; tot++; if(!son[x])return; dfs2(son[x],y); for(int i=0; i<v[x].size(); i++){ int to=v[x][i]; if(to!=son[x] && to!=fa[x])dfs2(to,to); } } void build(int x,int l,int r){ tree[x].l=l; tree[x].r=r; tree[x].len=r-l+1; if(l==r){ tree[x].sum=w[pre[l]]; return; } int mid=(l+r)/2; build(x*2,l,mid); build(x*2+1,mid+1,r); tree[x].sum=tree[x*2].sum+tree[x*2+1].sum; } inline void pushup(int x){ tree[x].sum=tree[x*2].sum+tree[x*2+1].sum; } inline void pushdown(int x){ if(tree[x].lazy){ int k=(tree[x].lazy==1)?1:0; tree[x*2].lazy=tree[x].lazy; tree[x*2].sum=k*tree[x*2].len; tree[x*2+1].lazy=tree[x].lazy; tree[x*2+1].sum=k*tree[x*2+1].len; tree[x].lazy=0; } } void change(int x,int l,int r,int k){ if(tree[x].l==l && tree[x].r==r){ tree[x].lazy=k; int kk=(k==1)?1:0; tree[x].sum=kk*tree[x].len; return; } pushdown(x); int mid=(tree[x].l+tree[x].r)/2; if(r<=mid)change(x*2,l,r,k); else if(l>mid)change(x*2+1,l,r,k); else change(x*2,l,mid,k),change(x*2+1,mid+1,r,k); pushup(x); } int query_sum(int x,int l,int r){ if(tree[x].l>=l && tree[x].r<=r)return tree[x].sum; pushdown(x); int mid=(tree[x].l+tree[x].r)/2; if(r<=mid)return query_sum(x*2,l,r); else if(l>mid)return query_sum(x*2+1,l,r); else return query_sum(x*2,l,mid)+query_sum(x*2+1,mid+1,r); } int find_sum(int x,int y){ int t1=top[x]; int t2=top[y]; int ans=0; while(t1!=t2){ if(deep[t1]<deep[t2]){ swap(t1,t2); swap(x,y); } ans+=query_sum(1,totree[t1],totree[x]); change(1,totree[t1],totree[x],1); x=fa[t1]; t1=top[x]; } if(deep[x]>deep[y])swap(x,y); ans+=query_sum(1,totree[x],totree[y]); change(1,totree[x],totree[y],1); return ans; } int main(){ n=rd(); for(int i=1; i<n; i++){ int x=rd(); link(x,i); } dfs1(0,1); dfs2(0,0); build(1,1,n); int Q=rd(); char op[15]; while(Q--){ scanf("%s",op); int x=rd(); if(op[0]=='i'){ if(query_sum(1,totree[x],totree[x]))puts("0"); else printf("%d\n",deep[x]-find_sum(x,0)); } else{ if(query_sum(1,totree[x],totree[x])){ printf("%d\n",query_sum(1,totree[x],totree[x]+num[x]-1)); change(1,totree[x],totree[x]+num[x]-1,-1); } else puts("0"); } } return 0; } |