#include <bits/stdc++.h>
#define FOR(i, a, b) for(int i = (int)a; i <= (int)b; ++i)
#define RFOR(i, a, b) for(int i = (int)a; i >= (int)b; --i)
#define in insert
#define pb push_back
#define fi first
#define se second
#define ll long long
#define ull unsigned long long
using namespace std;
const int MAX = 2e6 + 7;
const int BASE = 1 << 20;
int t[2 * BASE];
int tab[MAX], par[MAX], dp[MAX];
inline void update(int v, int w) {
t[v] = min(t[v], w);
while(v > 0) {
v >>= 1;
t[v] = min(t[2 * v], t[2 * v + 1]);
}
}
inline int query(int v, int a, int b, int c, int d) {
if(b < c || a > d) return 1e9;
if(a >= c && b <= d) return t[v];
int mid = a + b; mid >>= 1;
int res = min(query(2 * v, a, mid, c, d), query(2 * v + 1, mid + 1, b, c, d));
return res;
}
void solve() {
int n; cin >> n;
FOR(i, 1, n) cin >> tab[i];
FOR(i, 1, n) tab[i + n] = tab[i];
FOR(i, 0, 2 * BASE - 1) t[i] = 1e9;
RFOR(i, 2 * n, 1) {
int val = tab[i];
int akt = query(1, 1, BASE - 1, val + 1, BASE - 1);
if(akt == 1e9) par[i] = 0;
else par[i] = akt;
update(val + BASE - 1, i);
}
RFOR(i, 2 * n, 1) dp[i] = dp[par[i]] + 1;
int res = 0;
FOR(i, 1, 2 * n) res = max(res, dp[i]);
cout << res;
}
int main() {
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
solve();
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 | #include <bits/stdc++.h> #define FOR(i, a, b) for(int i = (int)a; i <= (int)b; ++i) #define RFOR(i, a, b) for(int i = (int)a; i >= (int)b; --i) #define in insert #define pb push_back #define fi first #define se second #define ll long long #define ull unsigned long long using namespace std; const int MAX = 2e6 + 7; const int BASE = 1 << 20; int t[2 * BASE]; int tab[MAX], par[MAX], dp[MAX]; inline void update(int v, int w) { t[v] = min(t[v], w); while(v > 0) { v >>= 1; t[v] = min(t[2 * v], t[2 * v + 1]); } } inline int query(int v, int a, int b, int c, int d) { if(b < c || a > d) return 1e9; if(a >= c && b <= d) return t[v]; int mid = a + b; mid >>= 1; int res = min(query(2 * v, a, mid, c, d), query(2 * v + 1, mid + 1, b, c, d)); return res; } void solve() { int n; cin >> n; FOR(i, 1, n) cin >> tab[i]; FOR(i, 1, n) tab[i + n] = tab[i]; FOR(i, 0, 2 * BASE - 1) t[i] = 1e9; RFOR(i, 2 * n, 1) { int val = tab[i]; int akt = query(1, 1, BASE - 1, val + 1, BASE - 1); if(akt == 1e9) par[i] = 0; else par[i] = akt; update(val + BASE - 1, i); } RFOR(i, 2 * n, 1) dp[i] = dp[par[i]] + 1; int res = 0; FOR(i, 1, 2 * n) res = max(res, dp[i]); cout << res; } int main() { ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); solve(); return 0; } |
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