Submission #417285

#	Time	Username	Problem	Language	Result	Execution time	Memory
417285		maomao90	Event Hopping 2 (JOI21_event2)	C++17	7 / 100	234 ms	28452 KiB

event2

#include <bits/stdc++.h> 
using namespace std;

template <class T>
inline bool mnto(T& a, T b) {return a > b ? a = b, 1 : 0;}
template <class T>
inline bool mxto(T& a, T b) {return a < b ? a = b, 1: 0;}
#define REP(i, s, e) for (int i = s; i < e; i++)
#define RREP(i, s, e) for (int i = s; i >= e; i--)
typedef long long ll;
typedef long double ld;
#define MP make_pair
#define FI first
#define SE second
typedef pair<int, int> ii;
typedef pair<ll, ll> pll;
#define MT make_tuple
typedef tuple<int, int, int> iii;
#define ALL(_a) _a.begin(), _a.end()
#define pb emplace_back
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<ii> vii;

#define INF 1000000005
#define LINF 1000000000000000005
#define MOD 1000000007
#define MAXN 200005

int n, k;
ii lr[MAXN];
vi events;
set<int> st;
map<int, int> mp;
int d[MAXN];
vi ans;

int v[MAXN * 4];
void update(int p, int x, int u, int lo, int hi) {
	int mid = lo + hi >> 1;
	if (lo == hi) {
		v[u] = x;
		return;
	}
	int lc = u * 2, rc = u * 2 + 1;
	if (p <= mid) update(p, x, lc, lo, mid);
	else update(p, x, rc, mid + 1, hi);
	v[u] = max(v[lc], v[rc]);
}
void update(int p, int x) {
	update(p, x, 1, 0, 2 * n);
}
int query(int s, int e, int u, int lo, int hi) {
	if (lo >= s && hi <= e) {
		return v[u];
	}
	int mid = lo + hi >> 1;
	int lc = u * 2, rc = u * 2 + 1;
	if (e <= mid) return query(s, e, lc, lo, mid);
	else if (s > mid) return query(s, e, rc, mid + 1, hi);
	else return max(query(s, e, lc, lo, mid), query(s, e, rc, mid + 1, hi));
}
int query(int s, int e) {
	return query(s, e, 1, 0, 2 * n);
}

int main() {
	scanf("%d%d", &n, &k);
	REP (i, 0, n) {
		scanf("%d%d", &lr[i].FI, &lr[i].SE);
		st.insert(lr[i].FI);
		st.insert(lr[i].SE);
	}
	int ptr = 0;
	for (auto i : st) {
		mp[i] = ptr++;
	}
	REP (i, 0, n) {
		lr[i].FI = mp[lr[i].FI];
		lr[i].SE = mp[lr[i].SE];
	}
	REP (i, 0, n) {
		if (events.empty() || lr[events.back()].FI != lr[i].FI ||
				lr[events.back()].SE > lr[i].SE) {
			mp[lr[i].FI] = events.size();
			events.pb(i);
		}
	}
	RREP (i, events.size() - 1, 0) {
		int l = lr[events[i]].FI, r = lr[events[i]].SE;
		d[i] = query(r, 2 * n) + 1;
		update(l, d[i]);
	}
	int prvr = -1;
	REP (i, 0, events.size()) {
		if (k == 0) break;
		int l = lr[events[i]].FI, r = lr[events[i]].SE;
		if (d[i] >= k && l >= prvr) {
			ans.pb(events[i]);
			prvr = r;
			k--;
		}
	}
	if (ans.empty()) {
		printf("-1\n");
		return 0;
	} else {
		for (int i : ans) {
			printf("%d\n", i + 1);
		}
	}
	return 0;
}

/*
4 2
1 4
3 5
4 9
7 10

12 3
1 4
1 8
1 3
1 2
1 4
3 8
3 5
3 9
6 11
6 10
6 12
6 7

6 1
1 7
2 5
2 4
4 8
4 7
8 9

6 4
1 3
1 2
2 4
4 5
5 6
6 7
*/

Compilation message (stderr)

event2.cpp: In function 'void update(int, int, int, int, int)':
event2.cpp:40:15: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   40 |  int mid = lo + hi >> 1;
      |            ~~~^~~~
event2.cpp: In function 'int query(int, int, int, int, int)':
event2.cpp:57:15: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   57 |  int mid = lo + hi >> 1;
      |            ~~~^~~~
event2.cpp: In function 'int main()':
event2.cpp:8:40: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    8 | #define REP(i, s, e) for (int i = s; i < e; i++)
......
   95 |  REP (i, 0, events.size()) {
      |       ~~~~~~~~~~~~~~~~~~~               
event2.cpp:95:2: note: in expansion of macro 'REP'
   95 |  REP (i, 0, events.size()) {
      |  ^~~
event2.cpp:68:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   68 |  scanf("%d%d", &n, &k);
      |  ~~~~~^~~~~~~~~~~~~~~~
event2.cpp:70:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   70 |   scanf("%d%d", &lr[i].FI, &lr[i].SE);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 0 / 1
• Subtask 3: 0 / 31
• Subtask 4: 0 / 61