#include "shortcut.h"
#include <cassert>
#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
using llg = long long;
using pii = pair<llg, llg>;
const llg BIG = (llg)(1e9) * (llg)(1e7);
llg nbSta;
llg lenShortcut;
llg lenMap;
inline pii finAutor(llg tempsVise, llg debutShort, vector<llg> &pos, vector<llg> &poids, const vector<vector<llg>> &table, llg &maxAvant)
{
pii finPos {0, BIG};
int dd = max(0LL, debutShort-1);
if (maxAvant == -13) dd = 0;
for (llg sta = dd; sta < debutShort; ++sta) {
maxAvant = max(maxAvant, poids[sta] - pos[sta]);
int dm = poids[sta] + pos[sta] + maxAvant;
if (dm > tempsVise) return {-1, -1};
}
llg posDebut = pos[debutShort];
for (llg sta = debutShort; sta < nbSta; ++sta) {
llg risqueApres = table[sta][debutShort] - posDebut;
bool canAvant = (poids[sta] + pos[sta] + maxAvant <= tempsVise);
llg risqueAvant = posDebut + maxAvant;
if (canAvant) risqueAvant = -BIG;
if (canAvant && risqueApres < 0) continue;
llg tempsPlus = tempsVise - max(risqueApres, risqueAvant) - lenShortcut - poids[sta];
if (tempsPlus < 0) return {-1, -1};
finPos.first = max(finPos.first, pos[sta] - tempsPlus);
finPos.second = min(finPos.second, pos[sta] + tempsPlus);
}
return finPos;
}
vector<vector<llg>> t1, t2;
void genTable(vector<vector<llg>> &table, llg tempsVise, vector<llg> &pos, vector<llg> &poids)
{
for (llg sta = 0; sta < nbSta; ++sta) {
table[sta].resize(sta+1);
table[sta][sta] = -BIG;
llg maxAutor = tempsVise - poids[sta] - pos[sta];
llg curMax = -BIG;
for (llg prev = sta-1; prev >= 0; --prev) {
llg valPrev = poids[prev] - pos[prev];
if (valPrev > maxAutor) { // Ne peut pas etre attellg direct
curMax = max(curMax, poids[prev] + pos[prev]);
}
table[sta][prev] = curMax;
}
}
}
bool estPossibleGlob(llg tempsVise, vector<llg> &pos, vector<llg> &revPos, vector<llg> &poids, vector<llg> &revPoids)
{
vector<pii> finToDebut(nbSta);
vector<bool> vu(nbSta, false);
genTable(t1, tempsVise, revPos, revPoids);
llg maxAvant = -BIG;
auto gen = [&] (int sta) {
llg o = 13;
pii x = finAutor(tempsVise, nbSta-1-sta, revPos, revPoids, t1, o);
finToDebut[sta] = {lenMap - x.second, lenMap - x.first};
};
genTable(t2, tempsVise, pos, poids);
maxAvant = -BIG;
for (llg deb = 0; deb < nbSta; ++deb) {
pii posFinOk = finAutor(tempsVise, deb, pos, poids, t2, maxAvant);
for (llg fin = deb; fin < nbSta; ++fin) {
if (pos[fin] > posFinOk.second) break;
if (posFinOk.first <= pos[fin] && pos[fin] <= posFinOk.second) {
if (! vu[fin]) {
gen(fin);
vu[fin] = true;
}
auto corDebOk = finToDebut[fin];
if (corDebOk.first <= pos[deb] && pos[deb] <= corDebOk.second) {
return true;
}
}
}
}
return false;
}
long long find_shortcut(int _n, std::vector<int> _l, std::vector<int> _d, int _c)
{
nbSta = _n;
lenShortcut = _c;
vector<llg> pos, revPos;
vector<llg> poids, revPoids;
pos.resize(nbSta);
revPos.resize(nbSta);
poids.resize(nbSta);
revPoids.resize(nbSta);
llg curPos = 0;
t1.resize(nbSta);
t2.resize(nbSta);
for (llg iSta = 0; iSta < nbSta; ++iSta) {
t1[iSta].resize(iSta+1);
t2[iSta].resize(iSta+1);
pos[iSta] = curPos;
if (iSta < nbSta-1) curPos += _l[iSta];
poids[iSta] = _d[iSta];
revPoids[iSta] = _d[nbSta-1-iSta];
}
lenMap = pos.back();
curPos = 0;
for (llg iSta = nbSta-1; iSta >= 0; --iSta) {
revPos[iSta] = curPos;
if (iSta > 0) curPos += _l[iSta-1];
}
reverse(revPos.begin(), revPos.end());
//reverse(revPoids.begin(), revPoids.end());
llg lo = 0, ri = 0;
pii toPr = {-1, -1};
for (int a = 0; a < nbSta; ++a) {
for (int b = a+1; b < nbSta; ++b) {
lo = max(lo, poids[a] + poids[b] + min(lenShortcut, pos[b] - pos[a]));
llg newRi = max(ri, poids[a] + poids[b] + (pos[b] - pos[a]));
if (newRi > ri) {
newRi = ri;
toPr = {a, b};
}
}
}
auto gd = [&] (int a, int b) {
llg r1 = abs(pos[a] - pos[b]);
llg r2 = abs(pos[a] - pos[toPr.first]) + lenShortcut + abs(pos[b] - pos[toPr.second]);
llg r3 = abs(pos[a] - pos[toPr.second]) + lenShortcut + abs(pos[b] - pos[toPr.first]);
return min(r1, min(r2, r3));
};
ri = 0;
for (int a = 0; a < nbSta; ++a) {
for (int b = a+1; b < nbSta; ++b) {
ri = max(ri, poids[a] + poids[b] + gd(a, b));
}
}
while (lo < ri) {
llg mid = (lo + ri) / 2;
if (estPossibleGlob(mid, pos, revPos, poids, revPoids)) {
ri = mid;
} else {
lo = mid+1;
}
}
return lo;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
2 ms |
376 KB |
n = 4, 80 is a correct answer |
| 2 |
Correct |
2 ms |
256 KB |
n = 9, 110 is a correct answer |
| 3 |
Incorrect |
2 ms |
376 KB |
n = 4, incorrect answer: jury 21 vs contestant 22 |
| 4 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
2 ms |
376 KB |
n = 4, 80 is a correct answer |
| 2 |
Correct |
2 ms |
256 KB |
n = 9, 110 is a correct answer |
| 3 |
Incorrect |
2 ms |
376 KB |
n = 4, incorrect answer: jury 21 vs contestant 22 |
| 4 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
2 ms |
376 KB |
n = 4, 80 is a correct answer |
| 2 |
Correct |
2 ms |
256 KB |
n = 9, 110 is a correct answer |
| 3 |
Incorrect |
2 ms |
376 KB |
n = 4, incorrect answer: jury 21 vs contestant 22 |
| 4 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
2 ms |
376 KB |
n = 4, 80 is a correct answer |
| 2 |
Correct |
2 ms |
256 KB |
n = 9, 110 is a correct answer |
| 3 |
Incorrect |
2 ms |
376 KB |
n = 4, incorrect answer: jury 21 vs contestant 22 |
| 4 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
2 ms |
376 KB |
n = 4, 80 is a correct answer |
| 2 |
Correct |
2 ms |
256 KB |
n = 9, 110 is a correct answer |
| 3 |
Incorrect |
2 ms |
376 KB |
n = 4, incorrect answer: jury 21 vs contestant 22 |
| 4 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
2 ms |
376 KB |
n = 4, 80 is a correct answer |
| 2 |
Correct |
2 ms |
256 KB |
n = 9, 110 is a correct answer |
| 3 |
Incorrect |
2 ms |
376 KB |
n = 4, incorrect answer: jury 21 vs contestant 22 |
| 4 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
2 ms |
376 KB |
n = 4, 80 is a correct answer |
| 2 |
Correct |
2 ms |
256 KB |
n = 9, 110 is a correct answer |
| 3 |
Incorrect |
2 ms |
376 KB |
n = 4, incorrect answer: jury 21 vs contestant 22 |
| 4 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
2 ms |
376 KB |
n = 4, 80 is a correct answer |
| 2 |
Correct |
2 ms |
256 KB |
n = 9, 110 is a correct answer |
| 3 |
Incorrect |
2 ms |
376 KB |
n = 4, incorrect answer: jury 21 vs contestant 22 |
| 4 |
Halted |
0 ms |
0 KB |
- |
