#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef long double ld;
typedef complex<ld> cd;
typedef pair<int, int> pi;
typedef pair<ll,ll> pl;
typedef pair<ld,ld> pd;
typedef vector<int> vi;
typedef vector<ld> vd;
typedef vector<ll> vl;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
typedef vector<cd> vcd;
template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag,tree_order_statistics_node_update>;
#define FOR(i, a, b) for (int i=a; i<(b); i++)
#define F0R(i, a) for (int i=0; i<(a); i++)
#define FORd(i,a,b) for (int i = (b)-1; i >= a; i--)
#define F0Rd(i,a) for (int i = (a)-1; i >= 0; i--)
#define sz(x) (int)(x).size()
#define mp make_pair
#define pb push_back
#define f first
#define s second
#define lb lower_bound
#define ub upper_bound
#define all(x) x.begin(), x.end()
const int MOD = 1000000007;
const ll INF = 1e18;
const int MX = 1000001;
int N, a[MX], ans;
bitset<MX> done;
set<int> tmp[MX];
int main() {
ios_base::sync_with_stdio(0); cin.tie(0);
cin >> N;
FOR(i,1,N+1) {
cin >> a[i];
tmp[a[i]].insert(i);
}
FOR(i,1,N+1) if (!done[i]) {
ans ++;
int cur = i;
while (1) {
tmp[a[cur]].erase(cur); done[cur] = 1;
auto it = tmp[a[cur]-1].lb(cur);
if (it == tmp[a[cur]-1].end()) break;
cur = *it;
}
}
cout << ans;
}
/* Look for:
* the exact constraints (multiple sets are too slow for n=10^6 :( )
* special cases (n=1?)
* overflow (ll vs int?)
* array bounds
*/
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
48 ms |
47352 KB |
Output is correct |
2 |
Correct |
44 ms |
47472 KB |
Output is correct |
3 |
Correct |
55 ms |
47792 KB |
Output is correct |
4 |
Correct |
44 ms |
47984 KB |
Output is correct |
5 |
Execution timed out |
2063 ms |
91716 KB |
Time limit exceeded |
6 |
Execution timed out |
2052 ms |
100164 KB |
Time limit exceeded |
7 |
Correct |
1784 ms |
100164 KB |
Output is correct |
8 |
Correct |
1781 ms |
100164 KB |
Output is correct |
9 |
Execution timed out |
2060 ms |
102776 KB |
Time limit exceeded |
10 |
Correct |
1894 ms |
107424 KB |
Output is correct |