#include <iostream>
#include <cmath>
#include <algorithm>
#include <vector>
#include <set>
#include <unordered_set>
#include <queue>
#include <deque>
#include <string>
#include <sstream>
#include <iomanip>
#include <map>
#include <unordered_map>
#include <stack>
#include <cstdio>
#include <climits>
#include <tuple>
#include <ctime>
#include <cstring>
#include <numeric>
#include <functional>
#include <chrono>
#include <cassert>
#include <bitset>
#include <fstream>
//#include <bit>
//#include <ranges>
//#include <numbers>
#define sz(a) ((int)((a).size()))
// printf("%.10f\n", ans);
/*ofstream fout("timeline.out");
ifstream fin("timeline.in");*/
using ll = long long;
using namespace std;
const ll mod = 998244353;
const int N = 2e5 + 5, inf = 1e9;
int n, q, a, b, c, d, ans;
vector<int> h, dp, nge, pge, ind;
vector<vector<int>> go1, go2;
void NGE()
{
stack<int> s;
s.push(0);
for (int i = 1; i < n; i++)
{
if (s.empty())
{
s.push(i);
continue;
}
while (!s.empty() && h[s.top()] < h[i])
{
nge[s.top()] = i;
s.pop();
}
s.push(i);
}
while (!s.empty())
{
nge[s.top()] = -1;
s.pop();
}
}
void PGE()
{
stack<int> s;
s.push(0);
pge[0] = -1;
for (int i = 1; i < n; i++)
{
while (!s.empty() && h[s.top()] < h[i]) s.pop();
if (s.empty()) pge[i] = -1;
else pge[i] = s.top();
s.push(i);
}
}
int dfs(int u)
{
if (dp[u] != inf + 1) return dp[u];
if (c <= u && u <= d) return dp[u] = 0;
int r = nge[u];
int ans = inf;
if (r != -1) ans = min(ans, dfs(r) + 1);
int l = pge[u];
if (l != -1) ans = min(ans, dfs(l) + 1);
return dp[u] = ans;
}
void solve()
{
/*dp = vector<int>(n, inf + 1);
ans = inf;
for (int i = a; i <= b; i++) ans = min(ans, dfs(i));
if (ans == inf) ans = -1;
cout << ans << "\n";*/
if (h[a] > h[c])
{
cout << "-1\n";
return;
}
int ans = 0, id = a;
for (int i = 19; i >= 0; i--)
{
int u = go1[id][i];
if (u < n && h[u] <= h[c])
{
ans += (1 << i);
id = u;
}
}
for (int i = 19; i >= 0; i--)
{
int u = go2[id][i];
if (u < n && h[u] <= h[c])
{
ans += (1 << i);
id = u;
}
}
if (id == c) cout << ans << "\n";
else cout << "-1\n";
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cin >> n >> q;
h = nge = pge = vector<int>(n);
ind = vector<int>(n + 1);
go1 = go2 = vector<vector<int>>(n, vector<int>(20));
for (int i = 0; i < n; i++) cin >> h[i];
NGE();
PGE();
for (int i = 0; i < n; i++) ind[h[i]] = i;
for (int i = n; i >= 1; i--)
{
int id = ind[i];
int l = pge[id], r = nge[id];
if (l == -1 || r == -1) go1[id][0] = n;
else
{
if (h[l] > h[r]) go1[id][0] = l;
else go1[id][0] = r;
}
for (int j = 1; j < 20; j++)
{
int u = go1[id][j - 1];
if (u == n) go1[id][j] = n;
else go1[id][j] = go1[u][j - 1];
}
if (l == -1 && r == -1) go2[id][0] = n;
else if (l == -1) go2[id][0] = r;
else if (r == -1) go2[id][0] = l;
else
{
if (h[l] < h[r]) go2[id][0] = l;
else go2[id][0] = r;
}
for (int j = 1; j < 20; j++)
{
int u = go2[id][j - 1];
if (u == n) go2[id][j] = n;
else go2[id][j] = go2[u][j - 1];
}
}
while (q--)
{
cin >> a >> b >> c >> d;
solve();
}
return 0;
}
Compilation message
/usr/bin/ld: /tmp/cc0zU3Hg.o: in function `main':
stub.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/ccVr6nai.o:jumps.cpp:(.text.startup+0x0): first defined here
/usr/bin/ld: /tmp/cc0zU3Hg.o: in function `main':
stub.cpp:(.text.startup+0x177): undefined reference to `init(int, std::vector<int, std::allocator<int> >)'
/usr/bin/ld: stub.cpp:(.text.startup+0x1d1): undefined reference to `minimum_jumps(int, int, int, int)'
collect2: error: ld returned 1 exit status
