#include <bits/stdc++.h>
using namespace std;
int main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
int n;
cin >> n;
vector<int> v(n);
for (auto& x : v) {
cin >> x;
}
deque<pair<int, int>> dq;
int res = 0;
for (int i = 0; i < n; ++i) {
if (dq.empty()) {
dq.push_back({i, v[i]});
} else {
auto [pos, value] = dq.back();
if (value < v[i]) {
dq.push_back({i, v[i]});
}
}
}
for (int i = n-1; i >= 0; --i) {
if (!dq.empty()) {
auto [pos, value] = dq.back();
if (pos == i) {
dq.pop_back();
}
}
while (!dq.empty()) {
auto& [pos, value] = dq.front();
if (value <= v[i]) {
dq.pop_front();
} else {
break;
}
}
dq.push_front({i, v[i]});
res = max(res, (int)dq.size());
}
cout << res << '\n';
return 0;
}
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 | #include <bits/stdc++.h> using namespace std; int main() { ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr); int n; cin >> n; vector<int> v(n); for (auto& x : v) { cin >> x; } deque<pair<int, int>> dq; int res = 0; for (int i = 0; i < n; ++i) { if (dq.empty()) { dq.push_back({i, v[i]}); } else { auto [pos, value] = dq.back(); if (value < v[i]) { dq.push_back({i, v[i]}); } } } for (int i = n-1; i >= 0; --i) { if (!dq.empty()) { auto [pos, value] = dq.back(); if (pos == i) { dq.pop_back(); } } while (!dq.empty()) { auto& [pos, value] = dq.front(); if (value <= v[i]) { dq.pop_front(); } else { break; } } dq.push_front({i, v[i]}); res = max(res, (int)dq.size()); } cout << res << '\n'; return 0; } |
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