#include <bits/stdc++.h>
#include "obstacles.h"
using namespace std;
static int N, M;
static vector<int> Tval, Hval;
static vector<int> c;
static vector<int> b;
static vector<int> sum;
static vector<int> l, r; // renamed left/right
// Segment trees
static vector<int> seg_min, seg_max;
// Build segment trees
void build_seg_min(int node, int nl, int nr) {
if (nl == nr) { seg_min[node] = Hval[nl]; return; }
int mid = (nl + nr) / 2;
build_seg_min(2*node, nl, mid);
build_seg_min(2*node+1, mid+1, nr);
seg_min[node] = min(seg_min[2*node], seg_min[2*node+1]);
}
void build_seg_max(int node, int nl, int nr) {
if (nl == nr) { seg_max[node] = Hval[nl]; return; }
int mid = (nl + nr) / 2;
build_seg_max(2*node, nl, mid);
build_seg_max(2*node+1, mid+1, nr);
seg_max[node] = max(seg_max[2*node], seg_max[2*node+1]);
}
int query_min(int node, int nl, int nr, int ql, int qr) {
if (qr < nl || nr < ql) return INT_MAX;
if (ql <= nl && nr <= qr) return seg_min[node];
int mid = (nl + nr) / 2;
return min(query_min(2*node, nl, mid, ql, qr),
query_min(2*node+1, mid+1, nr, ql, qr));
}
int query_max(int node, int nl, int nr, int ql, int qr) {
if (qr < nl || nr < ql) return INT_MIN;
if (ql <= nl && nr <= qr) return seg_max[node];
int mid = (nl + nr) / 2;
return max(query_max(2*node, nl, mid, ql, qr),
query_max(2*node+1, mid+1, nr, ql, qr));
}
// Wrappers
int call_min(int L, int R) { return query_min(1, 0, M-1, L, R); }
int call_max(int L, int R) { return query_max(1, 0, M-1, L, R); }
void initialize(vector<int> T, vector<int> H) {
Tval = T; Hval = H;
N = Tval.size(); M = Hval.size();
int d = Tval[0];
c.assign(M, 0);
b.assign(M, -1);
sum.assign(M, 0);
l.assign(M, 0);
r.assign(M, 0);
for(int i = 0; i < M; i++) c[i] = (Hval[i] >= d ? 1 : 0);
sum[0] = c[0];
for(int i = 1; i < M; i++) sum[i] = sum[i-1] + c[i];
int last = M;
for(int i = M-1; i >= 0; i--) {
if(c[i] == 1) last = i;
r[i] = last-1;
}
last = -1;
for(int i = 0; i < M; i++) {
if(c[i] == 1) last = i;
l[i] = last+1;
}
seg_min.assign(4*M, INT_MAX);
seg_max.assign(4*M, INT_MIN);
build_seg_min(1, 0, M-1);
build_seg_max(1, 0, M-1);
}
bool can_reach(int L, int R, int S, int D) {
bool st=false, en=false;
if(S > D) swap(S,D);
if(call_max(S,D) >= 3) return false;
int sad = l[S];
int happy = r[S];
if(call_min(sad, happy) == 0) st = true;
sad = l[D];
happy = r[D];
if(call_min(sad, happy) == 0) en = true;
if(st && en) return true;
if(sum[D]==sum[S-1]) return true;
return false;
}
