#include <bits/stdc++.h>
#define int LL
using namespace std;
#define PII pair<int, int>
#define VI vector<int>
#define VPII vector<PII>
#define LL long long
#define LD long double
#define f first
#define s second
#define MP make_pair
#define PB push_back
#define endl '\n'
#define ALL(c) (c).begin(), (c).end()
#define SIZ(c) (int)(c).size()
#define REP(i, n) for(int i = 0; i < (int)(n); ++i)
#define FOR(i, b, e) for(int i = (b); i <= (int)(e); ++i)
#define FORD(i, b, e) for(int i = (b); i >= (int)(e); --i)
#define ll LL
#define st f
#define nd s
#define pb PB
#define mp MP
#define eb emplace_back
#define siz(c) SIZ(c)
const int inf = 1e9+7;
const ll INF = 1e18L+7;
#define sim template<class n
sim, class s> ostream & operator << (ostream &p, pair<n, s> x)
{return p << "<" << x.f << ", " << x.s << ">";}
sim> auto operator << (ostream &p, n y) ->
typename enable_if<!is_same<n, string>::value, decltype(y.begin(), p)>::type
{int o = 0; p << "{"; for(auto c: y) {if(o++) p << ", "; p << c;} return p << "}";}
void dor() {cerr << endl;}
sim, class...s> void dor(n p, s...y) {cerr << p << " "; dor(y...);}
sim, class s> void mini(n &p, s y) {if(p>y) p = y;}
sim, class s> void maxi(n &p, s y) {if(p<y) p = y;}
#ifdef DEB
#define debug(...) dor(__FUNCTION__, ":", __LINE__, ": ", __VA_ARGS__)
#else
#define debug(...)
#endif
#define I(x) #x " =", (x), " "
#define A(a, i) #a "[" #i " =", i, "] =", a[i], " "
const int MAXN = 2e6+5;
int prev_biggereq[MAXN];
int in[MAXN];
int cnt[MAXN];
int32_t main()
{
int n;
cin >> n;
in[0] = 1e6+1;
FOR(i, 1, n) {
cin >> in[i];
in[i+n] = in[i];
}
FOR(i, 1, 2*n) {
prev_biggereq[i] = i-1;
while(in[prev_biggereq[i]] < in[i]) {
prev_biggereq[i] = prev_biggereq[prev_biggereq[i]];
}
debug(i, prev_biggereq[i]);
}
FOR(i, 1, n) {
cnt[prev_biggereq[i]]++;
}
int count_less_than_i = cnt[0];
int best = 0;
FOR(i, 1, n) {
debug(i, prev_biggereq[i], count_less_than_i);
maxi(best, count_less_than_i);
count_less_than_i += cnt[i];
cnt[prev_biggereq[i+n]]++;
cnt[prev_biggereq[i]]--;
if(prev_biggereq[i+n] <= i) count_less_than_i++;
if(prev_biggereq[i] <= i) count_less_than_i--;
}
cout << best << endl;
}
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 | #include <bits/stdc++.h> #define int LL using namespace std; #define PII pair<int, int> #define VI vector<int> #define VPII vector<PII> #define LL long long #define LD long double #define f first #define s second #define MP make_pair #define PB push_back #define endl '\n' #define ALL(c) (c).begin(), (c).end() #define SIZ(c) (int)(c).size() #define REP(i, n) for(int i = 0; i < (int)(n); ++i) #define FOR(i, b, e) for(int i = (b); i <= (int)(e); ++i) #define FORD(i, b, e) for(int i = (b); i >= (int)(e); --i) #define ll LL #define st f #define nd s #define pb PB #define mp MP #define eb emplace_back #define siz(c) SIZ(c) const int inf = 1e9+7; const ll INF = 1e18L+7; #define sim template<class n sim, class s> ostream & operator << (ostream &p, pair<n, s> x) {return p << "<" << x.f << ", " << x.s << ">";} sim> auto operator << (ostream &p, n y) -> typename enable_if<!is_same<n, string>::value, decltype(y.begin(), p)>::type {int o = 0; p << "{"; for(auto c: y) {if(o++) p << ", "; p << c;} return p << "}";} void dor() {cerr << endl;} sim, class...s> void dor(n p, s...y) {cerr << p << " "; dor(y...);} sim, class s> void mini(n &p, s y) {if(p>y) p = y;} sim, class s> void maxi(n &p, s y) {if(p<y) p = y;} #ifdef DEB #define debug(...) dor(__FUNCTION__, ":", __LINE__, ": ", __VA_ARGS__) #else #define debug(...) #endif #define I(x) #x " =", (x), " " #define A(a, i) #a "[" #i " =", i, "] =", a[i], " " const int MAXN = 2e6+5; int prev_biggereq[MAXN]; int in[MAXN]; int cnt[MAXN]; int32_t main() { int n; cin >> n; in[0] = 1e6+1; FOR(i, 1, n) { cin >> in[i]; in[i+n] = in[i]; } FOR(i, 1, 2*n) { prev_biggereq[i] = i-1; while(in[prev_biggereq[i]] < in[i]) { prev_biggereq[i] = prev_biggereq[prev_biggereq[i]]; } debug(i, prev_biggereq[i]); } FOR(i, 1, n) { cnt[prev_biggereq[i]]++; } int count_less_than_i = cnt[0]; int best = 0; FOR(i, 1, n) { debug(i, prev_biggereq[i], count_less_than_i); maxi(best, count_less_than_i); count_less_than_i += cnt[i]; cnt[prev_biggereq[i+n]]++; cnt[prev_biggereq[i]]--; if(prev_biggereq[i+n] <= i) count_less_than_i++; if(prev_biggereq[i] <= i) count_less_than_i--; } cout << best << endl; } |
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