| # | 제출 시각 | 아이디 | 문제 | 언어 | 결과 | 실행 시간 | 메모리 |
|---|---|---|---|---|---|---|---|
| 392656 | usachevd0 | Shortcut (IOI16_shortcut) | C++17 | 0 ms | 0 KiB |
이 제출은 이전 버전의 oj.uz에서 채점하였습니다. 현재는 제출 당시와는 다른 서버에서 채점을 하기 때문에, 다시 제출하면 결과가 달라질 수도 있습니다.
#pragma gcc optimize("Ofast")
#pragma gcc optimize("O3")
#pragma gcc optimize("no-stack-protector")
#pragma gcc optimize("unroll-loops")
#pragma gcc target("avx,avx2,ffa")
#include <bits/stdc++.h>
#ifndef DEBUG
#include "shortcut.h"
#endif
using namespace std;
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define all(a) (a).begin(), (a).end()
using ll = long long;
using ull = unsigned long long;
using pii = pair<int, int>;
using pil = pair<int, ll>;
using pli = pair<ll, int>;
using pll = pair<ll, ll>;
using ld = long double;
template<typename T1, typename T2> bool chkmin(T1& x, T2 y) {
return y < x ? (x = y, true) : false;
}
template<typename T1, typename T2> bool chkmax(T1& x, T2 y) {
return y > x ? (x = y, true) : false;
}
void debug_out() {
cerr << endl;
}
template<typename T1, typename... T2> void debug_out(T1 A, T2... B) {
cerr << ' ' << A;
debug_out(B...);
}
template<typename T> void mdebug_out(T* a, int n) {
for (int i = 0; i < n; ++i) {
cerr << a[i] << ' ';
}
cerr << endl;
}
#ifdef DEBUG
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#define mdebug(a, n) cerr << #a << ": ", mdebug_out(a, n)
#else
#define debug(...) 1337
#define mdebug(a, n) 1337
#endif
template<typename T> ostream& operator << (ostream& stream, const vector<T>& v) {
for (auto& x : v) {
stream << x << ' ';
}
return stream;
}
template<typename T1, typename T2> ostream& operator << (ostream& stream, const pair<T1, T2>& p) {
return stream << p.first << ' ' << p.second;
}
const ll inf64 = 1e18;
const int maxN = 3003;
ll sum_lo[maxN][maxN], sum_hi[maxN][maxN];
ll dif_lo[maxN][maxN], dif_hi[maxN][maxN];
ll x[maxN], d[maxN];
ll find_shortcut(int n, vector<int> dx, vector<int> _d, int c) {
for (int i = 0; i < n; ++i) d[i] = _d[i];
for (int i = 0; i + 1 < n; ++i) {
x[i + 1] = x[i] + dx[i];
}
auto good = [&](ll D) -> bool {
for (int i = 0; i <= n; ++i) {
fill(sum_lo[i], sum_lo[i] + n + 1, -inf64);
fill(sum_hi[i], sum_hi[i] + n + 1, +inf64);
fill(dif_lo[i], dif_lo[i] + n + 1, -inf64);
fill(dif_hi[i], dif_hi[i] + n + 1, +inf64);
}
for (int i = 0; i < n; ++i) {
for (int j = i + 1; j < n; ++j) {
if (d[i] + d[j] + x[j] - x[i] > D) {
ll T = D - d[i] - d[j] - c;
if (T < 0) {
return false;
}
sum_lo[i][j] = x[i] + x[j] - T;
sum_hi[i][j] = x[i] + x[j] + T;
dif_lo[i][j] = -T - x[i] + x[j];
dif_hi[i][j] = T + x[j] - x[i];
}
}
}
for (int i = n - 1; i >= 0; --i) {
for (int j = n - 1; j > i; --j) {
chkmax(sum_lo[i][j], sum_lo[i + 1][j]);
chkmax(sum_lo[i][j], sum_lo[i][j + 1]);
}
}
for (int i = 0; i < n; ++i) {
for (int j = i + 1; j < n; ++j) {
if (i > 0) chkmin(sum_hi[i][j], sum_hi[i - 1][j]);
if (j > 0) chkmin(sum_hi[i][j], sum_hi[i][j - 1]);
}
}
for (int i = 0; i < n; ++i) {
for (int j = n - 1; j > i; --j) {
if (i > 0) chkmax(dif_lo[i][j], dif_lo[i - 1][j]);
chkmax(dif_lo[i][j], dif_lo[i][j + 1]);
}
}
for (int i = n - 1; i >= 0; --i) {
for (int j = i + 1; j < n; ++j) {
chkmin(dif_hi[i][j], dif_hi[i + 1][j]);
if (j > 0) chkmin(dif_hi[i][j], dif_hi[i][j - 1]);
}
}
for (int l = 0; l < n; ++l) {
for (int r = l + 1; r < n; ++r) {
ll sum = x[l] + x[r];
ll dif = x[r] - x[l];
/*if (l == 1 && r == 3) {
debug(sum, dif);
debug(sum_lo[l][r], sum_hi[l][r]);
debug(dif_lo[l][r], dif_hi[l][r]);
}*/
if (sum_lo[l][r] <= sum && sum <= sum_hi[l][r] &&
dif_lo[l][r] <= dif && dif <= dif_hi[l][r])
{
return true;
}
}
}
return false;
};
ll vl = -1;
ll vr = 2 * max_element(d, d + n) + X[n - 1];
while (vr - vl > 1) {
ll vm = (vl + vr) >> 1;
if (good(vm)) {
vr = vm;
} else {
vl = vm;
}
}
return vr;
}
#ifdef DEBUG
int32_t main() {
#ifdef DEBUG
freopen("in", "r", stdin);
#endif
ios::sync_with_stdio(0);
cin.tie(0);
int n, c;
cin >> n >> c;
vector<int> l(n - 1), d(n);
for (int& x : l) cin >> x;
for (int& x : d) cin >> x;
cout << find_shortcut(n, l, d, c) << '\n';
return 0;
}
#endif