#include "bits/stdc++.h"
using namespace std;
int const N = 1e6+6;
int n, a[N], b[N], mx, mx_id, dp[N], ans;
vector <int> v;
int main(){
ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
cin >> n;
for(int i = 0; i < n; ++i){
cin >> a[i];
if(a[i] > mx){
mx = a[i];
mx_id = i;
}
}
int curr1 = (mx_id+1)%n, curr2 = 0;
for(;curr2 < n;){
b[curr2++] = a[curr1++];
if(curr1 >= n) curr1 = 0;
}
for(int i = n-1; ~i; --i){
while(v.size() && b[v.back()] <= b[i]) v.pop_back();
dp[i] = (v.empty() ? 0 : dp[v.back()]) + 1;
v.push_back(i);
ans = max(ans, dp[i]);
}
cout << ans << '\n';
}
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 | #include "bits/stdc++.h" using namespace std; int const N = 1e6+6; int n, a[N], b[N], mx, mx_id, dp[N], ans; vector <int> v; int main(){ ios::sync_with_stdio(0); cin.tie(0); cout.tie(0); cin >> n; for(int i = 0; i < n; ++i){ cin >> a[i]; if(a[i] > mx){ mx = a[i]; mx_id = i; } } int curr1 = (mx_id+1)%n, curr2 = 0; for(;curr2 < n;){ b[curr2++] = a[curr1++]; if(curr1 >= n) curr1 = 0; } for(int i = n-1; ~i; --i){ while(v.size() && b[v.back()] <= b[i]) v.pop_back(); dp[i] = (v.empty() ? 0 : dp[v.back()]) + 1; v.push_back(i); ans = max(ans, dp[i]); } cout << ans << '\n'; } |
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