結果
| 問題 |
No.2543 Many Meetings
|
| コンテスト | |
| ユーザー |
 fuppy_kyopro
|
| 提出日時 | 2023-11-24 21:51:20 |
| 言語 | C++17(gcc12) (gcc 12.3.0 + boost 1.87.0) |
| 結果 |
AC
|
| 実行時間 | 204 ms / 2,000 ms |
| コード長 | 6,293 bytes |
| コンパイル時間 | 14,809 ms |
| コンパイル使用メモリ | 310,904 KB |
| 最終ジャッジ日時 | 2025-02-18 00:00:58 |
|
ジャッジサーバーID （参考情報） |
judge5 / judge2 |
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| ファイルパターン | 結果 |
|---|---|
| sample | AC * 3 |
| other | AC * 40 |
ソースコード
//*
#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
//*/
#include <bits/stdc++.h>
// #include <atcoder/all>
// #include <atcoder/lazysegtree>
using namespace std;
// using namespace atcoder;
// #define _GLIBCXX_DEBUG
#define DEBUG(x) cerr << #x << ": " << x << endl;
#define DEBUG_VEC(v) \
cerr << #v << ":"; \
for (int iiiiiiii = 0; iiiiiiii < v.size(); iiiiiiii++) \
cerr << " " << v[iiiiiiii]; \
cerr << endl;
#define DEBUG_MAT(v) \
cerr << #v << endl; \
for (int iv = 0; iv < v.size(); iv++) { \
for (int jv = 0; jv < v[iv].size(); jv++) { \
cerr << v[iv][jv] << " "; \
} \
cerr << endl; \
}
typedef long long ll;
// #define int ll
#define vi vector<int>
#define vl vector<ll>
#define vii vector<vector<int>>
#define vll vector<vector<ll>>
#define vs vector<string>
#define pii pair<int, int>
#define pis pair<int, string>
#define psi pair<string, int>
#define pll pair<ll, ll>
template <class S, class T>
pair<S, T> operator+(const pair<S, T> &s, const pair<S, T> &t) {
return pair<S, T>(s.first + t.first, s.second + t.second);
}
template <class S, class T>
pair<S, T> operator-(const pair<S, T> &s, const pair<S, T> &t) { return pair<S, T>(s.first - t.first, s.second - t.second); }
template <class S, class T>
ostream &operator<<(ostream &os, pair<S, T> p) {
os << "(" << p.first << ", " << p.second << ")";
return os;
}
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define rep1(i, n) for (int i = 1; i <= (int)(n); i++)
#define rrep(i, n) for (int i = (int)(n)-1; i >= 0; i--)
#define rrep1(i, n) for (int i = (int)(n); i > 0; i--)
#define REP(i, a, b) for (int i = a; i < b; i++)
#define in(x, a, b) (a <= x && x < b)
#define all(c) c.begin(), c.end()
void YES(bool t = true) {
cout << (t ? "YES" : "NO") << endl;
}
void Yes(bool t = true) { cout << (t ? "Yes" : "No") << endl; }
void yes(bool t = true) { cout << (t ? "yes" : "no") << endl; }
void NO(bool t = true) { cout << (t ? "NO" : "YES") << endl; }
void No(bool t = true) { cout << (t ? "No" : "Yes") << endl; }
void no(bool t = true) { cout << (t ? "no" : "yes") << endl; }
template <class T>
bool chmax(T &a, const T &b) {
if (a < b) {
a = b;
return 1;
}
return 0;
}
template <class T>
bool chmin(T &a, const T &b) {
if (a > b) {
a = b;
return 1;
}
return 0;
}
#define UNIQUE(v) v.erase(std::unique(v.begin(), v.end()), v.end());
const ll inf = 1000000001;
const ll INF = (ll)1e18 + 1;
const long double pi = 3.1415926535897932384626433832795028841971L;
int popcount(ll t) { return __builtin_popcountll(t); }
// int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
// int dx2[8] = { 1,1,0,-1,-1,-1,0,1 }, dy2[8] = { 0,1,1,1,0,-1,-1,-1 };
vi dx = {0, 0, -1, 1}, dy = {-1, 1, 0, 0};
vi dx2 = {1, 1, 0, -1, -1, -1, 0, 1}, dy2 = {0, 1, 1, 1, 0, -1, -1, -1};
struct Setup_io {
Setup_io() {
ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
cout << fixed << setprecision(25);
}
} setup_io;
// const ll MOD = 1000000007;
const ll MOD = 998244353;
// #define mp make_pair
// #define endl '\n'
template <typename Semigroup>
struct DisjointSparseTable {
using F = function<Semigroup(Semigroup, Semigroup)>;
const F f;
vector<vector<Semigroup>> st;
DisjointSparseTable(const vector<Semigroup> v, const F f) : f(f) {
int b = 0;
while ((1 << b) <= v.size())
++b;
st.resize(b, vector<Semigroup>(v.size(), Semigroup()));
for (int i = 0; i < v.size(); i++)
st[0][i] = v[i];
for (int i = 1; i < b; i++) {
int shift = 1 << i;
for (int j = 0; j < v.size(); j += shift << 1) {
int t = min(j + shift, (int)v.size());
st[i][t - 1] = v[t - 1];
for (int k = t - 2; k >= j; k--)
st[i][k] = f(v[k], st[i][k + 1]);
if (v.size() <= t) break;
st[i][t] = v[t];
int r = min(t + shift, (int)v.size());
for (int k = t + 1; k < r; k++)
st[i][k] = f(st[i][k - 1], v[k]);
}
}
}
Semigroup query(int l, int r) {
if (l >= --r) return st[0][l];
int p = 31 - __builtin_clz(l ^ r);
return f(st[p][l], st[p][r]);
}
};
pll f(pll a, pll b) {
return min(a, b);
}
signed main() {
int n, k;
cin >> n >> k;
vector<pll> lr(n);
rep(i, n) {
cin >> lr[i].first >> lr[i].second;
}
sort(all(lr));
vector<pll> ini(n);
rep(i, n) {
ini[i] = pll(lr[i].second, i);
}
DisjointSparseTable<pll> dst(ini, f);
constexpr int K = 21;
vector dp(K, vector(n, pii(-1, -1)));
rep(i, n) {
int r = lr[i].second;
int idx = lower_bound(all(lr), pll(r, -1)) - lr.begin();
if (idx == n) {
dp[0][i] = pii(r, inf);
} else {
int mi = dst.query(idx, n).second;
dp[0][i] = pii(r, mi);
}
}
rep(ki, K - 2) {
rep(i, n) {
int r = dp[ki][i].first;
int idx = dp[ki][i].second;
if (idx == inf) {
dp[ki + 1][i] = pii(inf, inf);
continue;
}
dp[ki + 1][i] = dp[ki][idx];
}
}
ll ans = inf;
rep(i, n) {
int rem = k;
int now = i;
int last_r = inf;
int k = K - 1;
while (rem > 0) {
if (now == inf) {
break;
}
while (rem < (1 << k)) {
k--;
}
if (dp[k][now].first == inf) {
break;
}
last_r = dp[k][now].first;
now = dp[k][now].second;
rem -= (1 << k);
}
if (rem == 0) {
chmin(ans, last_r - lr[i].first);
}
}
if (ans == inf) {
cout << -1 << endl;
} else {
cout << ans << endl;
}
}