#include <bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define ll long long
#define mp(x, y) make_pair(x, y)
#define sz(v) ((int) (v).size())
#define all(v) (v).begin(), (v).end()
#define MASK(i) (1LL << (i))
#define BIT(x, y) (((x) >> (y)) & 1)
#define pb push_back
#define max_rng *max_element
#define min_rng *min_element
#define rep(i, n) for(int i = 1, _n = (n); i <= _n; ++i)
#define forn(i, a, b) for(int i = (a), _b = (b); i <= _b; ++i)
#define ford(i, a, b) for(int i = (a), _b = (b); i >= _b; --i)
template <class X, class Y>
inline bool maximize(X &x, Y y) {
return (x < y ? x = y, true : false);
}
template <class X, class Y>
inline bool minimize(X &x, Y y) {
return (x > y ? x = y, true : false);
}
template <class X>
inline void compress(vector<X> &a) {
sort(all(a));
a.resize(unique(all(a)) - a.begin());
}
int ctz(ll x) { return __builtin_ctzll(x); }
int lg(ll x) { return 63 - __builtin_clzll(x); }
int popcount(ll x) { return __builtin_popcount(x); }
mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rand(ll l, ll r) {
return l + abs((ll) rng()) % (r - l + 1);
}
const ll oo = (ll) 1e17;
const int inf = (ll) 1e9, mod = (ll) 1e9 + 7;
const int mxn = 1e6, mxm = 3e6;
const int LG = 17;
int n;
int a[mxn + 5];
struct Seg {
int n;
vector<pair<int, int>> st;
Seg(int n) : n(n) {
st.resize(n << 2);
build(1, 1, n);
}
void build(int i, int l, int r) {
if (l == r) {
st[i] = mp(a[l], l);
return;
}
int m = (l + r) >> 1;
build(2 * i, l, m);
build(2 * i + 1, m + 1, r);
st[i] = max(st[2 * i], st[2 * i + 1]);
}
void shutdown(int p) {
int i = 1;
for (int l = 1, r = n; l < r; ) {
int m = (l + r) >> 1;
if (p > m) {
l = m + 1;
i = 2 * i + 1;
}
else {
r = m;
i = 2 * i;
}
}
st[i] = mp(-inf, 0);
while (i > 1) {
i >>= 1;
st[i] = max(st[2 * i], st[2 * i + 1]);
}
}
pair<int, int> get(int i, int l, int r, int u, int v) {
if (l > v || r < u) return mp(-inf, 0);
if (l >= u && r <= v) return st[i];
int m = (l + r) >> 1;
pair<int, int> L = get(2 * i, l, m, u, v);
pair<int, int> R = get(2 * i + 1, m + 1, r, u, v);
return max(L, R);
}
pair<int, int> get(int u, int v) {
return get(1, 1, n, u, v);
}
};
int main(void) {
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
cin >> n;
rep(i, n) cin >> a[i];
Seg s(n);
int cnt = 0;
pair<int, int> start;
while ((start = s.get(1, n)) != mp(-inf, 0)) {
cnt++;
while (true) {
s.shutdown(start.se);
pair<int, int> nxt = s.get(start.se + 1, n);
if (start.fi - 1 != nxt.fi) break;
else start = nxt;
}
}
cout << cnt;
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
348 KB |
Output is correct |
2 |
Correct |
1 ms |
348 KB |
Output is correct |
3 |
Correct |
2 ms |
604 KB |
Output is correct |
4 |
Correct |
2 ms |
604 KB |
Output is correct |
5 |
Correct |
419 ms |
31828 KB |
Output is correct |
6 |
Correct |
438 ms |
35152 KB |
Output is correct |
7 |
Correct |
403 ms |
28900 KB |
Output is correct |
8 |
Correct |
359 ms |
28496 KB |
Output is correct |
9 |
Correct |
381 ms |
30524 KB |
Output is correct |
10 |
Correct |
432 ms |
31312 KB |
Output is correct |