Submission #757661

#	Time	Username	Problem	Language	Result	Execution time	Memory
757661		Rafi22	Toy Train (IOI17_train)	C++14	100 / 100	329 ms	1656 KiB

train

#include <bits/stdc++.h>

using namespace std;

#define endl '\n'
#define st first
#define nd second
#define pb push_back
#define sz(x) (int)(x).size()
#define all(x) (x).begin(), (x).end()
#define ll long long
ll mod=1000000007;
int inf=1000000007;
ll infl=1000000000000000007;

const int N=5007;

int a[N],r[N];
vector<int>G[N];
vector<int>RG[N];
int ile[N];
bool is[N];

vector<int> who_wins(vector<int>a,vector<int>r,vector<int>U,vector<int>V)
{
    int n=sz(a),m=sz(U);
    vector<int>ans(n,1);
    for(int i=0;i<m;i++)
    {
        G[U[i]].pb(V[i]);
        RG[V[i]].pb(U[i]);
    }
    while(true)
    {
        memset(ile,0,sizeof ile);
        memset(is,0,sizeof is);
        deque<int>Q;
        for(int i=0;i<n;i++)
        {
            if(r[i])
            {
                Q.pb(i);
                is[i]=1;
            }
        }
        while(sz(Q)>0)
        {
            int v=Q[0];
            Q.pop_front();
            for(auto u:RG[v])
            {
                if(is[u]) continue;
                ile[u]++;
                if(a[u]==1||ile[u]==sz(G[u]))
                {
                    is[u]=1;
                    Q.pb(u);
                }
            }
        }
        bool xd=0;
        for(int i=0;i<n;i++) if(!is[i]) ans[i]=0;
        for(int i=0;i<n;i++)
        {
            if(!r[i]) continue;
            int c=0;
            for(auto u:G[i]) if(is[u]) c++;
            if(c==0||(a[i]==0&&c!=sz(G[i])))
            {
                r[i]=0;
                xd=1;
                break;
            }
        }
        if(!xd) break;
    }
    return ans;
}
/*
vector<int> who_wins1(vector<int>a,vector<int>r,vector<int>U,vector<int>V)
{
    int n=sz(a),m=sz(U);
    vector<int>DP(n,0);
    vector<int>p(n,0);
    vector<int>q(n,0);
    for(int i=0;i<m;i++)
    {
        if(U[i]==V[i]) p[U[i]]=1;
        else q[U[i]]=1;
    }
    for(int i=n-1;i>=0;i--)
    {
        if(q[i]) DP[i]=DP[i+1];
        else DP[i]=r[i];
        if(p[i])
        {
            if(a[i]==0&&r[i]==0) DP[i]=0;
            if(a[i]==1&&r[i]==1) DP[i]=1;
        }
    }
    return DP;
}

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int n;
    cin>>n;
    vector<int>a(n),r(n);
    for(int i=0;i<n;i++)
    {
        a[i]=rand()%2;
        cout<<a[i]<<" ";
    }
    cout<<endl;
    for(int i=0;i<n;i++)
    {
        r[i]=rand()%2;
        cout<<r[i]<<" ";
    }
    cout<<endl;
    vector<int>U,V;
    for(int i=0;i<n-1;i++)
    {
        int t=rand()%3;
        if(t==0||t==2)
        {
            U.pb(i);
            V.pb(i);
        }
        if(t==1||t==2)
        {
            U.pb(i);
            V.pb(i+1);
        }
    }
    U.pb(n-1);
    V.pb(n-1);
    for(auto a:U) cout<<a<<" ";
    cout<<endl;
    for(auto a:V) cout<<a<<" ";
    cout<<endl;
    vector<int>x=who_wins(a,r,U,V);
    vector<int>y=who_wins1(a,r,U,V);
    for(auto a:x) cout<<a<<" ";
    cout<<endl;
    for(auto a:y) cout<<a<<" ";
    cout<<endl;

    return 0;
}*/

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