hdu 4366 线段树+dfs序列

#include<cstdio>
#include<cstring>
#include<cmath>
#include<string>
#include<map>
#include<algorithm>
#define MS(x,y) memset(x,y,sizeof(x))
#define pi acos(-1.0)
#define ls o<<1
#define rs o<<1|1
#define root 1,0,time-1
using namespace std;
void fre(){freopen("t.txt","r",stdin);}
typedef long long LL;
typedef unsigned long long ULL;
const int MAXN = 50005;
const int inf = 0x3f3f3f3f;
struct staff
{
int l,a,id;
}st[MAXN];
struct node
{
int v,next;
}e[MAXN];

int m,n,ed,time;
int head[MAXN],in[MAXN*2],out[MAXN*2],ans[MAXN],maxv[8*MAXN];
map<int,int>mp;

bool cmp(staff a,staff b)
{
return a.a > b.a;
}
void dfs(int x)
{
in[x] = time++;
for(int i = head[x]; i!=-1; i=e[i].next)
{
dfs(e[i].v);
}
out[x] = time++;
}
void init()
{
int fa;
ed = time = 0;
MS(head,-1);MS(ans,-1);MS(maxv,-1);
mp.clear();
for(int i = 1; i < n; ++i)
{
scanf("%d%d%d",&fa,&st[i].l,&st[i].a);
st[i].id = i;
mp[st[i].l] = i;
e[ed].v = i;
e[ed].next = head[fa];
head[fa] = ed++;
}
dfs(0);
sort(st+1,st+n,cmp);
}
int query(int ql,int qr,int o,int l,int r)
{
if(ql <= l && qr >= r) return maxv[o];
int m = l+(r-l)/2,ans = -1;
if(ql<= m) ans = query(ql,qr,ls,l,m);
if(qr > m) ans = max(query(ql,qr,rs,m+1,r),ans);
return ans;
}
void update(int p,int v,int o,int l,int r)
{
if(l==r) maxv[o] = v;
else
{
int m = l+(r-l)/2;
if(p <= m) update(p,v,ls,l,m);
else update(p,v,rs,m+1,r);
maxv[o] = max(maxv[ls],maxv[rs]);
}
}
int solve()
{
int f;
for(int i = 1; i <= m; ++i)
{
scanf("%d",&f);
if(ans[f]==-1) printf("-1\n");
else printf("%d\n",mp[ans[f]]);
}
}
int main()
{
// fre();
int i,j,t;
scanf("%d",&t);
while(t--)
{
scanf("%d%d",&n,&m);
init();

for(i = 1; i < n; i = j)
{
j = i;
while(j < n && st[i].a == st[j].a)//能力值相等，成一批
{
int id = st[j].id;
ans[id] = query(in[id]+1,out[id]-1,root);
j++;
}
j = i;
while(j < n && st[i].a == st[j].a)
{
int id = st[j].id;
update(in[id],st[j].l,root);
j++;
}
}
solve();
}
}