#include <bits/stdc++.h>
using namespace std;
#define fwd(i, a, n) for (int i = (a); i < (n); i++)
#define rep(i, n) fwd(i, 0, n)
#define all(X) X.begin(), X.end()
#define sz(X) int(size(X))
#define pb push_back
#define eb emplace_back
#define st first
#define nd second
using pii = pair<int, int>; using vi = vector<int>;
using ll = long long; using ld = long double;
#ifdef LOC
auto SS = signal(6, [](int) { *(int *)0 = 0; });
#define DTP(x, y) auto operator << (auto &o, auto a) -> decltype(y, o) { o << "("; x; return o << ")"; }
DTP(o << a.st << ", " << a.nd, a.nd);
DTP(for (auto i : a) o << i << ", ", all(a));
void dump(auto... x) { (( cerr << x << ", " ), ...) <<
'\n'; }
#define deb(x...) cerr << setw(4) << __LINE__ << ":[" #x "]: ", dump(x)
#else
#define deb(...) 0
#endif
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cout << fixed << setprecision(10);
int n; cin >> n;
vector<int> v(n);
rep(i, n)cin >> v[i];
int pos = 0;
rep(i, n)if(v[pos] < v[i])pos = i;
rotate(v.begin(), v.begin() + pos, v.end());
deb(v);
stack<pii> s;
s.push({v[0], 0});
vi bigger(n);
fwd(i, 1, n){
while(s.top().st < v[i])s.pop();
bigger[i] = s.top().nd;
s.push({v[i], i});
}
deb(bigger);
int res = 1;
vi l(n), r(n);
fwd(i, 1, n){
l[bigger[i]+1]++;
r[i]++;
}
for(int i = n-1; i >= 0; i--){
if(v[i] == v[0]){
r[0] += 1;
if(i + 1 < n)l[i+1]++;
break;
}
}
int current = 1;
deb(l);
deb(r);
fwd(i, 0, n){
current += l[i];
res = max(res, current);
deb(current, i);
current -= r[i];
}
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 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 | #include <bits/stdc++.h> using namespace std; #define fwd(i, a, n) for (int i = (a); i < (n); i++) #define rep(i, n) fwd(i, 0, n) #define all(X) X.begin(), X.end() #define sz(X) int(size(X)) #define pb push_back #define eb emplace_back #define st first #define nd second using pii = pair<int, int>; using vi = vector<int>; using ll = long long; using ld = long double; #ifdef LOC auto SS = signal(6, [](int) { *(int *)0 = 0; }); #define DTP(x, y) auto operator << (auto &o, auto a) -> decltype(y, o) { o << "("; x; return o << ")"; } DTP(o << a.st << ", " << a.nd, a.nd); DTP(for (auto i : a) o << i << ", ", all(a)); void dump(auto... x) { (( cerr << x << ", " ), ...) << '\n'; } #define deb(x...) cerr << setw(4) << __LINE__ << ":[" #x "]: ", dump(x) #else #define deb(...) 0 #endif int main(){ ios_base::sync_with_stdio(0); cin.tie(0); cout << fixed << setprecision(10); int n; cin >> n; vector<int> v(n); rep(i, n)cin >> v[i]; int pos = 0; rep(i, n)if(v[pos] < v[i])pos = i; rotate(v.begin(), v.begin() + pos, v.end()); deb(v); stack<pii> s; s.push({v[0], 0}); vi bigger(n); fwd(i, 1, n){ while(s.top().st < v[i])s.pop(); bigger[i] = s.top().nd; s.push({v[i], i}); } deb(bigger); int res = 1; vi l(n), r(n); fwd(i, 1, n){ l[bigger[i]+1]++; r[i]++; } for(int i = n-1; i >= 0; i--){ if(v[i] == v[0]){ r[0] += 1; if(i + 1 < n)l[i+1]++; break; } } int current = 1; deb(l); deb(r); fwd(i, 0, n){ current += l[i]; res = max(res, current); deb(current, i); current -= r[i]; } cout << res << "\n"; return 0; } |
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