제출 #729617

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
729617		Sam_a17	Event Hopping (BOI22_events)	C++17	50 / 100	1502 ms	37096 KiB

events

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

#ifndef ONLINE_JUDGE
#define dbg(x) cerr << #x <<" "; print(x); cerr << endl;
#else
#define dbg(x)
#endif

#define sz(x) (int)x.size()
#define len(x) (int)x.length()
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define clr(x) (x).clear()
#define uniq(x) x.resize(unique(all(x)) - x.begin());
#define blt __builtin_popcount

#define pb push_back
#define popf pop_front
#define popb pop_back
#define ld long double
#define ll long long

void print(long long t) { cerr << t; }
void print(int t) { cerr << t; }
void print(string t) { cerr << t; }
void print(char t) { cerr << t; }
void print(double t) { cerr << t; }
void print(long double t) { cerr << t; }
void print(unsigned long long t) { cerr << t; }

template <class T, class V> void print(pair <T, V> p);
template <class T> void print(vector <T> v);
template <class T> void print(set <T> v);
template <class T, class V> void print(map <T, V> v);
template <class T> void print(multiset <T> v);
template <class T, class V> void print(T v[], V n) { cerr << "["; for (int i = 0; i < n; i++) { print(v[i]); cerr << " "; } cerr << "]"; }
template <class T, class V> void print(pair <T, V> p) { cerr << "{"; print(p.first); cerr << ","; print(p.second); cerr << "}"; }
template <class T> void print(vector <T> v) { cerr << "[ "; for (T i : v) { print(i); cerr << " "; } cerr << "]"; }
template <class T> void print(set <T> v) { cerr << "[ "; for (T i : v) { print(i); cerr << " "; } cerr << "]"; }
template <class T> void print(multiset <T> v) { cerr << "[ "; for (T i : v) { print(i); cerr << " "; } cerr << "]"; }
template <class T, class V> void print(map <T, V> v) { cerr << "[ "; for (auto i : v) { print(i); cerr << " "; } cerr << "]"; }
template <class T, class V> void print(unordered_map <T, V> v) { cerr << "[ "; for (auto i : v) { print(i); cerr << " "; } cerr << "]"; }
template <class T> void print(deque <T> v) { cerr << "[ "; for (T i : v) { print(i); cerr << " "; } cerr << "]"; }

#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
#define nl '\n'

// for random generations
mt19937 myrand(chrono::steady_clock::now().time_since_epoch().count());
// mt19937 myrand(131);

// for grid problems
int dx[8] = { -1,0,1,0,1,-1,1,-1 };
int dy[8] = { 0,1,0,-1,1,1,-1,-1 };

// lowest / (1 << 17) >= 1e5 / (1 << 18) >= 2e5 / (1 << 21) >= 1e6
void fastIO() {
	ios_base::sync_with_stdio(false);
	cin.tie(nullptr); cout.tie(nullptr);
}
// file in/out
void setIO(string str = "") {
	fastIO();

	if (str == "input") {
		freopen("input.txt", "r", stdin);
		freopen("output.txt", "w", stdout);
	}
	else {
		// freopen("skis.in", "r", stdin);
		// freopen("skis.out", "w", stdout);
	}
}
// Indexed Set  
template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
const int N = 2e5 + 10, M = 5e3 + 10, inf = 1e8, LOG = 18;
int n, q, ord[N];
long long down[N][LOG];

struct node {
	long long l, r;
	long long id;

	bool operator<(const node &y) const { return l < y.l; }
};

vector<node> intervals;

struct segTreeMin {
  vector<pair<long long, int>> mTree;
  int size;
 
  void init(long long n) {
    size = 1;
    while(size < n)  {
      size *= 2;
    }
    mTree.assign(2 * size - 1, {INT64_MAX, -1});
  }
 
  void upd(int u, long long v, int ind, int x, int lx, int rx) { // set value at pos u
    if(rx - lx == 1) {
      mTree[x] = min(mTree[x], make_pair(v, ind));
      return;
    }
 
    int m = (lx + rx) / 2;
    if(u < m) {
      upd(u, v, ind, 2 * x + 1, lx, m);
    }else {
      upd(u, v, ind, 2 * x + 2, m, rx);
    }
    mTree[x] = min(mTree[2 * x + 1], mTree[2 * x + 2]);
  }
 
  void upd(int u, long long v, int ind) {
    upd(u, v, ind, 0, 0, size);
  }
 
  pair<long long, int> qry (int l, int r, int x, int lx, int rx) { // range queries
    if(l >= rx || lx >= r) {
      return {INT64_MAX, -1};
    }
    if(lx >= l && r >= rx) {
      return mTree[x];
    }
 
    int m = (rx + lx) / 2;
    auto s1 = qry(l, r, 2 * x + 1, lx, m);
    auto s2 = qry(l, r, 2 * x + 2, m, rx);
    return min(s1, s2);
  }
 
  auto qry(int l, int r) {
    return qry(l, r, 0, 0, size);
  }
};

segTreeMin seg_min;

void solve_() {
	cin >> n >> q;

	vector<int> compress;
	for(int i = 1; i <= n; i++) {
		int li, ri; cin >> li >> ri;
		intervals.push_back({li, ri, i});
		
		//
		compress.push_back(li);
		compress.push_back(ri);
	}

	sort(all(compress));
	uniq(compress);
	
	sort(all(intervals));

	seg_min.init(sz(compress) + 5);
	for(int i = 0; i < n; i++) {
		intervals[i].l = lower_bound(all(compress), intervals[i].l) - compress.begin() + 1;
		intervals[i].r = lower_bound(all(compress), intervals[i].r) - compress.begin() + 1;
		seg_min.upd(intervals[i].r, intervals[i].l, i);
		ord[intervals[i].id] = i;
	}

	for(int i = 0; i < n; i++) {
		for(int j = 0; j < LOG; j++) {
			down[i][j] = -1;
		}
	}

	for(int i = 1; i < n; i++) {
		auto ans = seg_min.qry(intervals[i].l, intervals[i].r + 1);
		if(ans.first < intervals[i].l) {
			down[i][0] = ans.second;
		}
	}

	for(int i = 1; i < LOG; i++) {
		for(int j = 0; j < n; j++) {
			if(down[j][i - 1] == -1) {
				down[j][i] = -1;
				continue;
			}
			down[j][i] = down[down[j][i - 1]][i - 1];
		}
	}

	for(int i = 0; i < n; i++) {
		dbg(make_pair(intervals[i].l, intervals[i].r))
	}

	while(q--) {
		int x, y; cin >> x >> y;
		x = ord[x], y = ord[y];
		if(x == y) {
			cout << 0 << '\n';
			continue;
		}

		if(intervals[x].r == intervals[y].r) {
			cout << 1 << '\n';
			continue;
		}

		if(intervals[x].r > intervals[y].r) {
			cout << "impossible" << '\n';
			continue;
		}
		int curr = y, aa = 0;
		for(int i = LOG - 1; i >= 0; i--) {
			if(down[curr][i] == -1) continue;
			if(intervals[down[curr][i]].l > intervals[x].r) {
				curr = down[curr][i];
				aa += 1 << i;
			}
		}

		if(down[curr][0] == -1) {
			if(intervals[curr].l > intervals[x].r) {
				cout << "impossible" << '\n';
			} else {
				cout << aa + 1 << '\n';
			}
		} else {
			aa += 1;
			if(intervals[curr].l > intervals[x].r) {
				cout << aa + 1 << '\n';
			} else {
				cout << aa << '\n';
			}
		}
	}

}

int main() {
	setIO();

	auto solve = [&](int test_case)-> void {
		for (int i = 1; i <= test_case; i++) {
			solve_();
		}
	};

	int test_cases = 1;
	// cin >> test_cases;
	solve(test_cases);

	return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

events.cpp: In function 'void setIO(std::string)':
events.cpp:69:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   69 |   freopen("input.txt", "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
events.cpp:70:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   70 |   freopen("output.txt", "w", stdout);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 15 / 15
• Subtask 4: 15 / 15
• Subtask 5: 0 / 20
• Subtask 6: 0 / 30