| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 546921 | fvogel499 | Roller Coaster Railroad (IOI16_railroad) | 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.
/*
* File created on 04/08/2022 at 21:58:56.
* Link to problem:
* Description:
* Time complexity: O()
* Space complexity: O()
* Status: ---
* Copyright: Ⓒ 2022 Francois Vogel
*/
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <functional>
using namespace std;
using namespace __gnu_pbds;
#define pii pair<int, int>
#define f first
#define s second
#define vi vector<int>
#define all(x) x.begin(), x.end()
#define size(x) (int)((x).size())
#define pb push_back
#define ins insert
#define cls clear
#define int ll
#define ll long long
#define ld long double
typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;
int plan_roller_coaster_act(vi from, vi to) {
set<int> av;
for (int i : from) av.ins(i);
for (int i : to) av.ins(i);
map<int, int> compress;
int kc = 0;
for (int i : av) compress[i] = kc++;
for (int i = 0; i < size(from); i++) from[i] = compress[from[i]];
for (int i = 0; i < size(to); i++) to[i] = compress[to[i]];
int n = size(compress);
vi graph [n];
vi revG [n];
for (int i = 0; i < size(from); i++) {
graph[from[i]].pb(to[i]);
revG[to[i]].pb(from[i]);
}
int sum = 0;
for (int i = 0; i < n-1; i++) {
sum += size(graph[i])-size(revG[i]);
if (sum > 1) return 1;
for (int j = 1; j > sum; j--) {
sum++;
graph[i].pb(i+1);
revG[i+1].pb(i);
}
}
bool vis [n];
for (int i = 0; i < n; i++) vis[i] = false;
queue<int> q;
q.push(0);
vis[0] = true;
while (!q.empty()) {
int x = q.front();
q.pop();
for (int y : graph[x]) if (!vis[y]) {
vis[y] = true;
q.push(y);
}
for (int y : revG[x]) if (!vis[y]) {
vis[y] = true;
q.push(y);
}
}
for (int i = 0; i < n; i++) if (!vis[i]) return i;
return 0;
}
int plan_roller_coaster(vector<signed> from, vector<signed> to) {
vi ifrom, ito;
for (int i : from) ifrom.pb(i);
for (int i : to) ito.pb(i);
return plan_roller_coaster_act(ifrom, ito);
}
signed main() {
cin.tie(0);
ios_base::sync_with_stdio(0);
int n;
cin >> n;
vector<signed> from(n), to(n);
for (int i = 0; i < n; i++) cin >> from[i];
for (int i = 0; i < n; i++) cin >> to[i];
cout << plan_roller_coaster(from, to) << endl;
cout.flush();
int d = 0;
d++;
}