#include <bits/stdc++.h>
#define ALL(x) (x).begin(), (x).end()
#define SZ(x) ((int)(x).size())
using namespace std;
#ifdef LOCAL
template<typename A, typename B>
auto&operator<<(auto&o,pair<A, B>p){return o<<"("<<p.first<<", "<<p.second<<")";}
auto operator<<(auto&o,auto x)->decltype(x.end(),o){o<<"{";int i=0;for(auto e:x)o<<&","[!i++]<<e;return o<<"}";}
#define debug(X...)cerr<<"["#X"]: ",[](auto...$){((cerr<<$<<"; "),...)<<endl;}(X)
#else
#define debug(...){}
#endif
using i64 = long long;
using ll = long long;
using pii = pair<int, int>;
using pll = pair<i64, i64>;
using vi = vector<int>;
using vll = vector<i64>;
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cout << fixed << setprecision(14);
cerr << fixed << setprecision(6);
int n;
cin >> n;
vi values(n);
for (int &x : values) { cin >> x; }
deque<pii> maxima;
maxima.emplace_back(values[0], n);
for (int i = 1; i < n; ++i) {
if (values[i] > maxima.back().first) {
maxima.emplace_back(values[i], n + i);
}
}
i64 ans = maxima.size();
debug(maxima.size());
for (int i = n - 1; i >= 0; --i) {
if (maxima.back().second == n + i) {
maxima.pop_back();
}
while (!maxima.empty() && maxima.front().first <= values[i]) {
maxima.pop_front();
}
maxima.emplace_front(values[i], i);
debug(i, maxima.size());
ans = max<i64>(ans, maxima.size());
}
cout << ans << "\n";
}
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 | #include <bits/stdc++.h> #define ALL(x) (x).begin(), (x).end() #define SZ(x) ((int)(x).size()) using namespace std; #ifdef LOCAL template<typename A, typename B> auto&operator<<(auto&o,pair<A, B>p){return o<<"("<<p.first<<", "<<p.second<<")";} auto operator<<(auto&o,auto x)->decltype(x.end(),o){o<<"{";int i=0;for(auto e:x)o<<&","[!i++]<<e;return o<<"}";} #define debug(X...)cerr<<"["#X"]: ",[](auto...$){((cerr<<$<<"; "),...)<<endl;}(X) #else #define debug(...){} #endif using i64 = long long; using ll = long long; using pii = pair<int, int>; using pll = pair<i64, i64>; using vi = vector<int>; using vll = vector<i64>; int main() { ios_base::sync_with_stdio(0); cin.tie(0); cout << fixed << setprecision(14); cerr << fixed << setprecision(6); int n; cin >> n; vi values(n); for (int &x : values) { cin >> x; } deque<pii> maxima; maxima.emplace_back(values[0], n); for (int i = 1; i < n; ++i) { if (values[i] > maxima.back().first) { maxima.emplace_back(values[i], n + i); } } i64 ans = maxima.size(); debug(maxima.size()); for (int i = n - 1; i >= 0; --i) { if (maxima.back().second == n + i) { maxima.pop_back(); } while (!maxima.empty() && maxima.front().first <= values[i]) { maxima.pop_front(); } maxima.emplace_front(values[i], i); debug(i, maxima.size()); ans = max<i64>(ans, maxima.size()); } cout << ans << "\n"; } |
English