Submission #249210

#	Time	Username	Problem	Language	Result	Execution time	Memory
249210		MarcoMeijer	Toy Train (IOI17_train)	C++14	100 / 100	595 ms	3832 KiB

train

#include "train.h"
#include <bits/stdc++.h>
using namespace std;
 
//macros
typedef long long ll;
typedef pair<int, int> ii;
typedef pair<ll, ll> lll;
typedef tuple<int, int, int> iii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<iii> viii;
typedef vector<ll> vll;
typedef vector<lll> vlll;
#define REP(a,b,c) for(int a=int(b); a<int(c); a++)
#define RE(a,c) REP(a,0,c)
#define RE1(a,c) REP(a,1,c+1)
#define REI(a,b,c) REP(a,b,c+1)
#define REV(a,b,c) for(int a=int(c-1); a>=int(b); a--)
#define INF 1e9
#define pb push_back
#define fi first
#define se second
#define sz size()
 
const int MX=6000;
 
int n, m;
vi a, r, u, v;
vi res;
set<int> adj[MX], rev[MX];
int cnt[MX];
vi R;
bitset<MX> visited;

vi f(bool A, vi x) { // O(n+m)
    vi ret;
    queue<int> q;
    RE(u,n) cnt[u] = 0;
    visited.reset();
    for(int u : x) q.push(u), visited[u] = 1;
    while(!q.empty()) {
        int u = q.front(); q.pop();
        ret.push_back(u);
        for(int v:rev[u]) {
            if(visited[v]) continue;
            cnt[v]++;
            if(a[v] ==  A) {
                q.push(v), visited[v] = 1;
            } else {
                if(cnt[v] == adj[v].sz) q.push(v), visited[v] = 1;
            }
        }
    }
    return ret;
}
vi getInv(vi x) {
    vi y;
    visited.reset();
    for(int u:x) visited[u] = 1;
    RE(u,n) if(!visited[u] && adj[u].sz) y.push_back(u);
    return y;
}
void removeFromGraph(int u) {
    for(int v:adj[u]) rev[v].erase(u);
    for(int v:rev[u]) adj[v].erase(u);
    adj[u].clear();
    rev[u].clear();
}
 
vi who_wins(vi A, vi _R, vi U, vi V) {
    a = A; r = _R; u = U; v = V;
    n = a.size(); m = u.size();
    res.resize(n);
 
    RE(i,m) adj[u[i]].insert(v[i]);
    RE(i,m) rev[v[i]].insert(u[i]);

    RE(u,n) if(r[u]) R.push_back(u);

    while(1) {
        vi y = f(1, R);
        vi x = getInv(y);
        if(x.sz == 0) {
            RE(u,n) if(adj[u].sz) res[u] = 1;
            return res;
        }
        vi z = f(0,x);
        for(int u:z) res[u] = 0;
        for(int u:z) removeFromGraph(u);
    }
}

Compilation message (stderr)

train.cpp: In function 'vi f(bool, vi)':
train.cpp:51:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
                 if(cnt[v] == adj[v].sz) q.push(v), visited[v] = 1;
                           ^

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 11 / 11
• Subtask 4: 11 / 11
• Subtask 5: 12 / 12
• Subtask 6: 51 / 51