#include "bits/stdc++.h"
// #include "grader.cpp"
#include "obstacles.h"
using namespace std;
#define ff first
#define ss second
#define all(v) v.begin(), v.end()
#define ll long long
#define pb push_back
#define pii pair<int, int>
#define pli pair<ll, int>
#define pll pair<ll, ll>
#define tr(i, c) for(auto i = c.begin(); i != c.end(); ++i)
#define wr puts("----------------")
#define mm make_pair
template<class T>bool umin(T& a,T b){if(a>b){a=b;return 1;}return 0;}
template<class T>bool umax(T& a,T b){if(a<b){a=b;return 1;}return 0;}
const int N = 2e5+5;
int l[N], r[N], d[N], rep[N], sz[N], row[N], col[N];
struct node {
int l, r, val;
} seg[N<<2];
void bld(int x, int l, int r){
seg[x].l=l, seg[x].r=r;
if(l==r){
seg[x].val=col[l];
return;
}
int mid=(l+r)>>1;
bld(x<<1, l, mid);
bld(x<<1|1, mid+1, r);
seg[x].val=max(seg[x<<1].val, seg[x<<1|1].val);
}
int qry(int x, int l, int r){
if(seg[x].l==l and seg[x].r==r)
return seg[x].val;
int mid=(seg[x].l+seg[x].r)>>1;
if(r<=mid)
return qry(x<<1, l, r);
else if(l>mid)
return qry(x<<1|1, l, r);
else
return max(qry(x<<1, l, mid), qry(x<<1|1, mid+1, r));
}
int find(int x){
if(rep[x]==x)
return x;
return rep[x]=find(rep[x]);
}
void merge(int a, int b){
a=find(a), b=find(b);
if(a==b)
return;
if(sz[a]<sz[b])
swap(a, b);
rep[b]=a, sz[a]+=sz[b];
}
void initialize(vector<int> t, vector<int> h){
int n=(int)t.size(), m=(int)h.size();
for(int i = 1; i <= n; ++i)
row[i]=t[i-1];
for(int j = 1; j <= m; ++j)
col[j]=h[j-1], rep[j]=j, sz[j]=1;
bld(1, 1, m);
stack<int> st;
for(int i = 1; i <= m; ++i){
while(!st.empty() and col[st.top()]>col[i])
st.pop();
if(!st.empty())
l[i]=st.top();
st.push(i);
}
while(!st.empty())
st.pop();
for(int i = m; i >= 1; --i){
while(!st.empty() and col[st.top()]>col[i])
st.pop();
if(!st.empty())
r[i]=st.top();
st.push(i);
}
vector<pii> v;
for(int i = 1; i <= m; ++i)
v.pb({col[i], i});
sort(all(v), greater<pii> ());
int mx=-1, now=0;
tr(it, v){
while(now<n and row[now+1]>col[it->ss])
umax(mx, row[++now]);
d[it->ss]=mx;
}
tr(it, v){
if(l[it->ss]!=0 and d[it->ss]>qry(1, l[it->ss], it->ss))
merge(l[it->ss], it->ss);
if(r[it->ss]!=0 and d[it->ss]>qry(1, it->ss, r[it->ss]))
merge(it->ss, r[it->ss]);
}
}
bool can_reach(int L, int R, int S, int D){
S++, D++;
return find(S)==find(D);
}
