| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 443961 | peijar | Comparing Plants (IOI20_plants) | C++17 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include "plants.h"
#include <bits/stdc++.h>
using namespace std;
/*
* Si h[i] < h[i+1], alors r[i+1] <= r[i]
* Si h[i] > h[i+1] alors r[i+1] >= r[i]
* Donc si on a r[i] != r[i+1] on peut comparer r[i] et r[i+1] !
* r[i+1] > r[i] => h[i+1] < h[i]
* r[i+1] < r[i] => h[i+1] > h[i]
*/
const int MAXN = 2e5;
int k;
int nbPlusGrands[MAXN], cntEq[MAXN][2];
vector<int> adj[MAXN];
int ordre[MAXN];
int nbDevant[MAXN];
bool reach[MAXN][MAXN];
int nbPlantes;
int disCircle(int x, int y) {
if (x < y)
return y - x;
return nbPlantes - x + y;
}
void init(int _k, vector<int> r) {
k = _k;
nbPlantes = r.size();
for (int iPlante = 0; iPlante < nbPlantes; ++iPlante) {
nbPlusGrands[iPlante] = r[iPlante];
}
if (k == 2) {
for (int i = nbPlantes - 1; i >= 0; --i) {
if (i == nbPlantes - 1) {
int x = 1;
while (x < nbPlantes and nbPlusGrands[x - 1] == nbPlusGrands[i])
x++;
cntEq[i][nbPlusGrands[i]] = x;
} else {
cntEq[i][nbPlusGrands[i]] = 1 + cntEq[i + 1][nbPlusGrands[i]];
}
}
} else if (2 * k > nbPlantes) {
for (int i = 0; i < nbPlantes; ++i)
nbDevant[i] = k - 1, ordre[i] = -1;
for (int iOrdre = 0; iOrdre < nbPlantes; ++iOrdre) {
vector<int> possibles;
for (int iPlante = 0; iPlante < nbPlantes; ++iPlante)
if (ordre[iPlante] == -1 and nbDevant[iPlante] == nbPlusGrands[iPlante])
possibles.push_back(iPlante);
while (possibles.size() > 1) {
int x = possibles.back();
possibles.pop_back();
int y = possibles.back();
possibles.pop_back();
if (disCircle(x, y) < k)
possibles.push_back(x);
else
possibles.push_back(y);
}
int x = possibles.back();
ordre[x] = iOrdre;
for (int iPlante = 0; iPlante < nbPlantes; ++iPlante)
if (disCircle(iPlante, x) < k and ordre[iPlante] == -1)
nbDevant[iPlante]--;
}
} else {
vector<bool> seen(nbPlantes);
for (int iPlante = 0; iPlante < nbPlantes; ++iPlante)
nbDevant[iPlante] = k - 1;
int nbRestant = nbPlantes;
while (nbRestant > 0) {
vector<int> pot;
for (int iPlante = 0; iPlante < nbPlantes; ++iPlante)
if (!seen[iPlante] and nbDevant[iPlante] == nbPlusGrands[iPlante])
pot.push_back(iPlante);
vector<int> possibles;
int nbPots = pot.size();
for (int iPot = 0; iPot < nbPots; ++iPot) {
int potAvant = iPot ? iPot - 1 : nbPots - 1;
if (potAvant != iPot and disCircle(pot[potAvant], pot[iPot]) >= k)
possibles.push_back(pot[iPot]);
}
for (int iPlante : possibles) {
for (int j = 0; j < nbPlantes; ++j)
if (disCircle(j, iPlante) < k and !seen[iPlante]) {
nbDevant[j]--;
adj[iPlante].push_back(j);
}
seen[iPlante] = false;
nbRestant--;
}
}
for (int i = 0; i < nbPlantes; ++i)
reach[i][i] = 1;
for (int i = 0; i < nbPlantes; ++i)
for (int j : adj[i])
reach[i][j] = 1;
for (int inter = 0; inter < nbPlantes; ++inter)
for (int i = 0; i < nbPlantes; ++i)
if (reach[i][inter])
for (int j = 0; j < nbPlantes; ++j)
if (reach[inter][j])
reach[i][j] = 1;
}
}
int compare_plants(int x, int y) {
if (k == 2) {
bool allSame1[2] = {true, true};
bool allSame2[2] = {true, true};
int dis1 = disCircle(x, y);
int dis2 = disCircle(y, x);
for (int b = 0; b < 2; ++b) {
allSame1[b] = cntEq[x][b] >= dis1;
allSame2[b] = cntEq[y][b] >= dis2;
}
if (allSame1[0] or allSame2[1])
return 1;
else if (allSame1[1] or allSame2[0])
return -1;
return 0;
} else if (2 * k > nbPlantes) {
return (ordre[x] < ordre[y] ? -1 : 1);
} else {
if (reach[x][y] and reach[y][x])
return 0;
if (reach[x][y])
return -1;
return 1;
}
return 0;
}