#ifdef Home #define _GLIBCXX_DEBUG #endif // Home #include <bits/stdc++.h> using namespace std; typedef long long ll; typedef long double ld; const int N = 1<<17; int n, k, Q, arr[N], cnt[N][21], LEFT[N], RIGHT[N]; ll use[N], T, nT; void solve_subtask3() { for(int i = 1; i <= n; ++ i) { for(int j = k; j; -- j) { cnt[i][j] = cnt[i - 1][j] + (arr[i] <= j); } } } main() { #ifdef Home freopen("input.txt", "r", stdin); freopen("output.txt", "w", stdout); #endif // Home ios_base::sync_with_stdio(0); cin.tie(0); cin >> n >> k >> Q; stack < int > st; for(int i = 1; i <= n; ++ i) { cin >> arr[i]; for(; !st.empty() && arr[i] >= arr[st.top()]; st.pop()); LEFT[i] = st.empty() ? 0 : st.top(); st.push(i); } for(; !st.empty(); st.pop()); for(int i = n; i; -- i) { for(; !st.empty() && arr[i] >= arr[st.top()]; st.pop()); RIGHT[i] = st.empty() ? n + 1 : st.top(); st.push(i); } queue < int > q; for(int a, b; Q --> 0;) { cin >> a >> b; ++ T; use[a] = T; q.push(a); for(; !q.empty();) { int v = q.front(); q.pop(); int l = v - 1, r = v + 1, m = 1; for(; l && m;) { m &= arr[l] < arr[v]; if(use[l] < T) { use[l] = use[v] + 1; q.push(l); } l = LEFT[l]; } for(m = 1; r <= n && m;) { m &= arr[r] < arr[v]; if(use[r] < T) { use[r] = use[v] + 1; q.push(r); } r = RIGHT[r]; } } cout << use[b] - T - 1 << '\n'; T += n; } }

railway_trip.cpp:25:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   25 | main() {
      | ^~~~