Submission #417225

#	Time	Username	Problem	Language	Result	Execution time	Memory
417225		maomao90	Event Hopping 2 (JOI21_event2)	C++17	0 / 100	67 ms	17212 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;
map<int, int> mp;
vi adj[MAXN];
vi ans;

int d[MAXN], p[MAXN];;
void dfs(int u) {
	for (int v : adj[u]) {
		d[v] = d[u] + 1;
		p[v] = u;
		dfs(v);
	}
}

int main() {
	scanf("%d%d", &n, &k);
	REP (i, 0, n) {
		scanf("%d%d", &lr[i].FI, &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);
		}
	}
	mp[INF] = events.size();
	REP (i, 0, events.size()) {
		int r = lr[events[i]].SE;
		int nxt = mp.lower_bound(r) -> SE;
		adj[nxt].pb(i);
	}
	dfs(events.size());
	int i = mp.begin() -> SE;
	while (1) {
		if (k == 0) break;
		int l = lr[events[i]].FI;
		for (; i >= 0 && lr[events[i]].FI == l; i--) {
			if (d[i] < k) {
				i++;
				if (lr[events[i]].FI != l) {
					printf("-1\n");
					return 0;
				}
				ans.pb(events[i]);
				i = p[i];
				break;
			}
		}
		if (i < 0 || lr[events[i]].FI <= l) {
			i++;
			ans.pb(events[i]);
			i = p[i];
		}
		k--;
	}
	//assert(ans.size() == k);
	for (int i : ans) {
		printf("%d\n", i + 1);
	}
	//REP (i, 0, events.size() + 1) {
		//printf("%d:", i);
		//for (int v : adj[i]) {
			//printf(" %d", v);
		//}
		//printf("\n");
	//}
}

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

8 3
1 4
1 3
1 2
3 8
3 5
6 11
6 10
6 7
*/

Compilation message (stderr)

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++)
......
   59 |  REP (i, 0, events.size()) {
      |       ~~~~~~~~~~~~~~~~~~~               
event2.cpp:59:2: note: in expansion of macro 'REP'
   59 |  REP (i, 0, events.size()) {
      |  ^~~
event2.cpp:47:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   47 |  scanf("%d%d", &n, &k);
      |  ~~~~~^~~~~~~~~~~~~~~~
event2.cpp:49:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   49 |   scanf("%d%d", &lr[i].FI, &lr[i].SE);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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