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QOJ
ID | 题目 | 提交者 | 结果 | 用时 | 内存 | 语言 | 文件大小 | 提交时间 | 测评时间 |
---|---|---|---|---|---|---|---|---|---|
#327215 | #3307. Query on a Tree 17 | 11d10xy | WA | 2ms | 7036kb | C++14 | 2.1kb | 2024-02-14 20:37:02 | 2024-02-14 20:37:02 |
Judging History
answer
#include<bits/stdc++.h>
using namespace std;
using i64=long long;
int n,m,fa[100010][25],dep[100010],top[100010],dfn[100010],raw[100010],sz[100010],tot;
basic_string<int>G[100010];
i64 tag[100010<<2],sum[100010<<2];
auto app=[](int u,int len,i64 w){sum[u]+=w*len,tag[u]+=w;};
auto pushdown=[](int u,int len){
app(u<<1,len+1>>1,tag[u]),
app(u<<1|1,len>>1,tag[u]),tag[u]=0;
};
void mdf(int u,int l,int r,int L,int R){
if(L<=l&&r<=R)return app(u,r-l+1,1);
int mid=l+r>>1;
pushdown(u,r-l+1);
if(L<=mid)mdf(u<<1,l,mid,L,R);
if(R>mid)mdf(u<<1|1,mid+1,r,L,R);
sum[u]=sum[u<<1]+sum[u<<1|1];
}
i64 qry(int u,int l,int r,int L,int R){
if(L<=l&&r<=R)return sum[u];
int mid=l+r>>1;
pushdown(u,r-l+1);
return(L<=mid?qry(u<<1,l,mid,L,R):0)+(R>mid?qry(u<<1|1,mid+1,r,L,R):0);
}
inline i64 qry(int u){return qry(1,1,n,dfn[u],dfn[u]+sz[u]-1);}
void dfs1(int u){
sz[u]=1,dep[u]=dep[fa[u][0]]+1;
if(fa[u][0])G[u].erase(find(begin(G[u]),end(G[u]),fa[u][0]));
for(int i=1;fa[u][i]=fa[fa[u][i-1]][i-1];i++);
for(int&v:G[u]){
fa[v][0]=u,dfs1(v),sz[u]+=sz[v];
if(sz[v]>sz[G[u][0]])swap(v,G[u][0]);
}
}
void dfs2(int u,int t){
top[u]=t,dfn[u]=++tot,raw[tot]=u;
for(int v:G[u])dfs2(v,v==G[u][0]?t:v);
}
i64 findv(int u,int l,int r,i64 v){//找到第一个>v的
if(l==r)return raw[l];
int mid=l+r>>1;
pushdown(u,r-l+1);
return sum[u<<1]<=v?findv(u<<1|1,mid+1,r,v-sum[u<<1]):findv(u<<1,l,mid,v);
}
int main(){
cin>>n;
for(int i=1,u,v;i<n;i++)scanf("%d%d",&u,&v),G[u]+=v,G[v]+=u;
dfs1(1),dfs2(1,1);
cin>>m;
for(int op,u,v;m--;){
scanf("%d%d",&op,&u);
if(op==1)mdf(1,1,n,dfn[u],dfn[u]+sz[u]-1);
else{
scanf("%d",&v);
for(;top[u]!=top[v];u=fa[top[u]][0]){
if(dep[top[u]]<dep[top[v]])swap(u,v);
mdf(1,1,n,dfn[top[u]],dfn[u]);
}
}
i64 h=sum[1]/2;
u=findv(1,1,n,h);
for(int i=20;i>=0;i--)(v=fa[u][i])&&qry(v)<=h&&(u=v);
printf("%d\n",qry(u)>h?u:(u==1?1:fa[u][0]));
}
return 0;
}
详细
Test #1:
score: 100
Accepted
time: 2ms
memory: 7036kb
input:
7 1 6 1 7 7 3 3 2 7 5 5 4 4 1 2 1 4 1 6 2 6 7
output:
2 7 7 1
result:
ok 4 lines
Test #2:
score: -100
Wrong Answer
time: 2ms
memory: 6952kb
input:
15 1 2 1 3 2 4 3 7 6 2 3 8 4 9 2 5 5 11 7 13 10 4 11 15 12 5 14 7 11 2 6 11 1 6 2 10 9 1 9 2 2 6 1 4 2 7 6 1 2 2 8 13 1 10 2 8 15
output:
6 6 6 2 6 4 2 2 2 2 2
result:
wrong answer 1st lines differ - expected: '2', found: '6'