#include <bits/stdc++.h>
using namespace std;
#define rep(i,a,n) for (int i=a;i<n;i++)
#define per(i,a,n) for (int i=n-1;i>=a;i--)
#define pb push_back
#define mp make_pair
#define all(x) (x).begin(),(x).end()
#define fi first
#define se second
#define SZ(x) ((int)(x).size())
typedef vector<int> VI;
typedef long long ll;
typedef pair<int,int> PII;
typedef double db;
//mt19937 mrand(random_device{}());
const ll mod=1000000007;
//int rnd(int x) { return mrand() % x;}
ll powmod(ll a,ll b) {ll res=1;a%=mod; assert(b>=0); for(;b;b>>=1){if(b&1)res=res*a%mod;a=a*a%mod;}return res;}
int gcd(int a,int b) { return b?gcd(b,a%b):a;}
// head
const int N=1e6+5;
#define INF 0x3f3f3f3f
template<class T> inline void read(T &x) {
x=0; int c=getchar(),f=1;
for (;!isdigit(c);c=getchar()) if (c==45) f=-1;
for (;isdigit(c);c=getchar()) (x*=10)+=f*(c-'0');
}
int a[N],cnt[N],st[2*N];
int main() {
int n;
scanf("%d",&n);
rep(i,0,n) scanf("%d",&a[i]);
int top=0;
rep(i,0,2*n) {
int val=a[i%n];
while (top&&a[st[top-1]%n]<val) top--;
int ptr_1=top?st[top-1]+1:0;
if (ptr_1<i-n+1) ptr_1=i-n+1;
int ptr_2=(i<n)?i:n-1;
if (ptr_1<=ptr_2) {
cnt[ptr_1]++;
cnt[ptr_2+1]--;
}
st[top++]=i;
}
int ans=0,pref=0;
rep(i,0,n) {
pref+=cnt[i];
ans=max(ans,pref);
}
printf("%d\n",ans);
}
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 | #include <bits/stdc++.h> using namespace std; #define rep(i,a,n) for (int i=a;i<n;i++) #define per(i,a,n) for (int i=n-1;i>=a;i--) #define pb push_back #define mp make_pair #define all(x) (x).begin(),(x).end() #define fi first #define se second #define SZ(x) ((int)(x).size()) typedef vector<int> VI; typedef long long ll; typedef pair<int,int> PII; typedef double db; //mt19937 mrand(random_device{}()); const ll mod=1000000007; //int rnd(int x) { return mrand() % x;} ll powmod(ll a,ll b) {ll res=1;a%=mod; assert(b>=0); for(;b;b>>=1){if(b&1)res=res*a%mod;a=a*a%mod;}return res;} int gcd(int a,int b) { return b?gcd(b,a%b):a;} // head const int N=1e6+5; #define INF 0x3f3f3f3f template<class T> inline void read(T &x) { x=0; int c=getchar(),f=1; for (;!isdigit(c);c=getchar()) if (c==45) f=-1; for (;isdigit(c);c=getchar()) (x*=10)+=f*(c-'0'); } int a[N],cnt[N],st[2*N]; int main() { int n; scanf("%d",&n); rep(i,0,n) scanf("%d",&a[i]); int top=0; rep(i,0,2*n) { int val=a[i%n]; while (top&&a[st[top-1]%n]<val) top--; int ptr_1=top?st[top-1]+1:0; if (ptr_1<i-n+1) ptr_1=i-n+1; int ptr_2=(i<n)?i:n-1; if (ptr_1<=ptr_2) { cnt[ptr_1]++; cnt[ptr_2+1]--; } st[top++]=i; } int ans=0,pref=0; rep(i,0,n) { pref+=cnt[i]; ans=max(ans,pref); } printf("%d\n",ans); } |
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