#include <bits/stdc++.h>
using namespace std;
#define rep(i, a, b) for (int i = a; i < (b); ++i)
#define all(x) begin(x), end(x)
#define sz(x) (int)(x).size()
#define YES cout << "YES\n"
#define NO cout << "NO\n"
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef long double ld;
#ifdef LOCAL
#define DTP(x, y) \
auto operator<<(auto &o, auto a)->decltype(y, o) \
{ \
o << "("; \
x; \
return o << ")"; \
}
DTP(o << a.first << ", " << a.second, a.second);
DTP(for (auto i : a) o << i << ", ", all(a));
void dump(auto... x) { ((cerr << x << ", "), ...) << '\n'; }
#define debug(x...) cerr << setw(4) << __LINE__ << ":[" #x "]: ", dump(x)
#else
#define debug(...) 42
#endif
stringstream os;
void testing()
{
os = stringstream();
/*
Here create tests by pushing to os (<<).
*/
os.seekg(0, ios::beg);
cin.rdbuf(os.rdbuf());
}
struct Stree
{
int size;
vi V;
Stree(int n)
{
size = 1;
while (size < n)
size *= 2;
V.resize(size * 2, 0);
}
void put(int i, int val)
{
i += size;
while (i)
{
V[i] = max(V[i], val);
i /= 2;
}
}
int find(int i, int j)
{
int ans = 0;
i += size;
j += size;
while (i <= j)
{
if (i & 1)
ans = max(ans, V[i++]);
if (!(j & 1))
ans = max(ans, V[j--]);
i /= 2;
j /= 2;
}
return ans;
}
};
void solve()
{
int n;
cin >> n;
vi V(n);
for (auto &a : V)
cin >> a;
for (int i = 0; i < n; i++)
V.push_back(V[i]);
vector<pii> D(sz(V), {-1, 1});
for (int i = sz(V) - 2; i >= 0; i--)
{
int j = i + 1;
while (j > 0 && V[i] >= V[j])
j = D[j].first;
D[i].first = j;
if (j > 0)
D[i].second = D[j].second + 1;
}
int ans = 0;
for (auto &[x, y] : D)
ans = max(ans, y);
cout << ans << endl;
}
int main()
{
cin.tie(0)->sync_with_stdio(0);
cin.exceptions(cin.failbit);
int Z = 1;
// cin >> Z;
while (Z--)
solve();
}
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 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 | #include <bits/stdc++.h> using namespace std; #define rep(i, a, b) for (int i = a; i < (b); ++i) #define all(x) begin(x), end(x) #define sz(x) (int)(x).size() #define YES cout << "YES\n" #define NO cout << "NO\n" typedef long long ll; typedef pair<int, int> pii; typedef pair<ll, ll> pll; typedef vector<int> vi; typedef vector<ll> vl; typedef long double ld; #ifdef LOCAL #define DTP(x, y) \ auto operator<<(auto &o, auto a)->decltype(y, o) \ { \ o << "("; \ x; \ return o << ")"; \ } DTP(o << a.first << ", " << a.second, a.second); DTP(for (auto i : a) o << i << ", ", all(a)); void dump(auto... x) { ((cerr << x << ", "), ...) << '\n'; } #define debug(x...) cerr << setw(4) << __LINE__ << ":[" #x "]: ", dump(x) #else #define debug(...) 42 #endif stringstream os; void testing() { os = stringstream(); /* Here create tests by pushing to os (<<). */ os.seekg(0, ios::beg); cin.rdbuf(os.rdbuf()); } struct Stree { int size; vi V; Stree(int n) { size = 1; while (size < n) size *= 2; V.resize(size * 2, 0); } void put(int i, int val) { i += size; while (i) { V[i] = max(V[i], val); i /= 2; } } int find(int i, int j) { int ans = 0; i += size; j += size; while (i <= j) { if (i & 1) ans = max(ans, V[i++]); if (!(j & 1)) ans = max(ans, V[j--]); i /= 2; j /= 2; } return ans; } }; void solve() { int n; cin >> n; vi V(n); for (auto &a : V) cin >> a; for (int i = 0; i < n; i++) V.push_back(V[i]); vector<pii> D(sz(V), {-1, 1}); for (int i = sz(V) - 2; i >= 0; i--) { int j = i + 1; while (j > 0 && V[i] >= V[j]) j = D[j].first; D[i].first = j; if (j > 0) D[i].second = D[j].second + 1; } int ans = 0; for (auto &[x, y] : D) ans = max(ans, y); cout << ans << endl; } int main() { cin.tie(0)->sync_with_stdio(0); cin.exceptions(cin.failbit); int Z = 1; // cin >> Z; while (Z--) solve(); } |
English