QOJ.ac
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 |
---|---|---|---|---|---|---|---|---|---|
#72514 | #5148. Tree Distance | JinTianHao | TL | 2ms | 16256kb | C++17 | 2.9kb | 2023-01-16 14:05:49 | 2023-01-16 14:05:56 |
Judging History
answer
#include <bits/stdc++.h>
#define inf 1000000007
#define mod 1000000007
#define lowbit(x) (x&(-x))
// #define int long long
// #pragma GCC optimize("Ofast","inline","-ffast-math")
// #pragma GCC target("avx,sse2,sse3,sse4,mmx")
using namespace std;
template <typename T> void read(T &x){
x=0;char ch=getchar();int fh=1;
while (ch<'0'||ch>'9'){if (ch=='-')fh=-1;ch=getchar();}
while (ch>='0'&&ch<='9')x=x*10+ch-'0',ch=getchar();
x*=fh;
}
template <typename T> void write(T x) {
if (x<0) x=-x,putchar('-');
if (x>9) write(x/10);
putchar(x%10+'0');
}
template <typename T> void writeln(T x) {
write(x);
puts("");
}
int n,q,rt,all,len,tot;
int h[200005],e[400005],w[400005],ne[400005],idx;
int siz[200005],maxp[200005],id[200005];
long long dist[200005],bit[200005],ans[1000005];
bool vis[200005];
struct oper
{
int l,r;
long long v;
bool operator<(const oper &o) const
{
return (l^o.l?l>o.l:v>o.v);
}
}opr[2000005];
void modify(int x,long long y)
{
while(x<=n)
{
bit[x]=min(bit[x],y);
x+=lowbit(x);
}
}
long long query(int x)
{
long long res=1ll*inf*inf;
while(x)
{
res=min(res,bit[x]);
x-=lowbit(x);
}
return res;
}
void add(int a,int b,int c)
{
e[idx]=b,w[idx]=c,ne[idx]=h[a],h[a]=idx++;
}
void getrt(int x,int fa)
{
siz[x]=1;maxp[x]=0;
for(int i=h[x];~i;i=ne[i])
{
int j=e[i];
if(j==fa||vis[j]) continue;
getrt(j,x);siz[x]+=siz[j];
maxp[x]=max(maxp[x],siz[j]);
}
maxp[x]=max(maxp[x],all-siz[x]);
if(maxp[rt]>maxp[x]) rt=x;
}
void dfs(int x,int fa)
{
id[++len]=x;
for(int i=h[x];~i;i=ne[i])
{
int j=e[i];
if(j==fa||vis[j]) continue;
dist[j]=dist[x]+w[i];dfs(j,x);
}
}
void solve(int x)
{
dist[x]=0;id[len=1]=x;
for(int i=h[x];~i;i=ne[i])
{
int j=e[i];
if(vis[j]) continue;
dist[j]=w[i];dfs(j,x);
}
sort(id+1,id+len+1,[](int x,int y){return dist[x]<dist[y];});
set<int> st;
for(int i=1;i<=len;++i)
{
auto it=st.lower_bound(id[i]);
if(it!=st.end()) opr[++tot]={id[i],*it,dist[id[i]]+dist[*it]};
if(it!=st.begin()) --it,opr[++tot]={*it,id[i],dist[*it]+dist[id[i]]};
st.insert(id[i]);
}
}
void divide(int x)
{
vis[x]=1;
solve(x);
for(int i=h[x];~i;i=ne[i])
{
int j=e[i];
if(vis[j]) continue;
maxp[rt=0]=all=siz[j];
getrt(j,0);getrt(rt,0);
divide(rt);
}
}
signed main()
{
// freopen(".in","r",stdin);
// freopen(".out","w",stdout);
read(n);memset(h,-1,sizeof(h));
for(int i=1;i<n;++i)
{
int a,b,c;
read(a);read(b);read(c);
add(a,b,c);add(b,a,c);
}
maxp[rt=0]=all=n;
getrt(1,0);getrt(rt,0);
divide(rt);
read(q);
for(int i=1,l,r;i<=q;++i)
{
read(l);read(r);
opr[++tot]={l,r,-i};
}
sort(opr+1,opr+tot+1);memset(bit,0x3f,sizeof(bit));
for(int i=1;i<=tot;++i)
if(opr[i].v>0) modify(opr[i].r,opr[i].v);
else ans[-opr[i].v]=query(opr[i].r);
for(int i=1;i<=q;++i)
writeln(ans[i]==1ll*inf*inf?-1:ans[i]);
return 0;
}
詳細信息
Test #1:
score: 100
Accepted
time: 2ms
memory: 16256kb
input:
5 1 2 5 1 3 3 1 4 4 3 5 2 5 1 1 1 4 2 4 3 4 2 5
output:
-1 3 7 7 2
result:
ok 5 number(s): "-1 3 7 7 2"
Test #2:
score: -100
Time Limit Exceeded
input:
199999 31581 23211 322548833 176307 196803 690953895 34430 82902 340232856 36716 77480 466375266 7512 88480 197594480 95680 61864 679567992 19572 14126 599247796 188006 110716 817477802 160165 184035 722372640 23173 188594 490365246 54801 56250 304741654 10103 45884 643490340 127469 154479 214399361...