#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define st first
#define nd second
#define pb push_back
#define pii pair<int,int>
#define pll pair<ll,ll>
const int maxn = 1e6+7,maxlog = 21;
int tab[2*maxn];
int nxt[2*maxn];
int jump[2*maxn][maxlog];
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
int n;
cin>>n;
for(int i=1;i<=n;i++){
cin>>tab[i];
tab[i+n] = tab[i];
}
stack<pii> stos;
nxt[2*n+1] = 2*n+1;
for(int i=0;i<maxlog;i++)
jump[2*n+1][i] = 2*n+1;
for(int i=2*n;i>=1;i--){
while(stos.size() > 0 && stos.top().st <= tab[i]){
stos.pop();
}
if(stos.size() == 0)
nxt[i] = 2*n+1;
else
nxt[i] = stos.top().nd;
stos.push({tab[i],i});
jump[i][0] = nxt[i];
for(int j=1;j<maxlog;j++){
jump[i][j] = jump[jump[i][j-1]][j-1];
}
}
/*
for(int i=1;i<=2*n+1;i++){
cout<<i<<" nxt:"<<nxt[i]<<"\n";
}
*/
int wyn = 0,akt,x;
for(int i=1;i<=n;i++){
x = i;
akt = 1;
for(int j=maxlog-1;j>=0;j--){
if(jump[x][j] > i+n-1)
continue;
akt += (1<<j);
x = jump[x][j];
}
wyn = max(wyn,akt);
}
cout<<wyn<<"\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 71 72 73 | #include <bits/stdc++.h> using namespace std; typedef long long ll; #define st first #define nd second #define pb push_back #define pii pair<int,int> #define pll pair<ll,ll> const int maxn = 1e6+7,maxlog = 21; int tab[2*maxn]; int nxt[2*maxn]; int jump[2*maxn][maxlog]; int main(){ ios_base::sync_with_stdio(0); cin.tie(0); int n; cin>>n; for(int i=1;i<=n;i++){ cin>>tab[i]; tab[i+n] = tab[i]; } stack<pii> stos; nxt[2*n+1] = 2*n+1; for(int i=0;i<maxlog;i++) jump[2*n+1][i] = 2*n+1; for(int i=2*n;i>=1;i--){ while(stos.size() > 0 && stos.top().st <= tab[i]){ stos.pop(); } if(stos.size() == 0) nxt[i] = 2*n+1; else nxt[i] = stos.top().nd; stos.push({tab[i],i}); jump[i][0] = nxt[i]; for(int j=1;j<maxlog;j++){ jump[i][j] = jump[jump[i][j-1]][j-1]; } } /* for(int i=1;i<=2*n+1;i++){ cout<<i<<" nxt:"<<nxt[i]<<"\n"; } */ int wyn = 0,akt,x; for(int i=1;i<=n;i++){ x = i; akt = 1; for(int j=maxlog-1;j>=0;j--){ if(jump[x][j] > i+n-1) continue; akt += (1<<j); x = jump[x][j]; } wyn = max(wyn,akt); } cout<<wyn<<"\n"; return 0; } |
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