Submission #441060

#	Time	Username	Problem	Language	Result	Execution time	Memory
441060		fcmalkcin	Virus Experiment (JOI19_virus)	C++17	100 / 100	268 ms	40256 KiB

virus

#include <bits/stdc++.h>
using namespace std;
#define ll  long long
#define pll pair<ll,ll>
#define ff first
#define ss second
#define pb push_back
//#define endl "\n"
const ll maxn=1e6+10;
const ll mod =998244353 ;
const ll base=3e18;


ll a[812][812];
ll ax[5]= {-1,0,1,0};
ll ay[5]= {0,1,0,-1};
ll msk[17];
ll cntnw=0;
ll chk[812][812];
ll p,n, m;
ll ans[812][812];
bool dd[maxn];
ll hsh(ll x,ll y)
{
    return (x-1)*m+y;
}
ll par[maxn];
ll find_par(ll u)
{
    if (par[u]<0)
        return u;
    return par[u]=find_par(par[u]);
}
void dsu(ll x,ll y)
{
    x=find_par(x);
    y=find_par(y);
    if (dd[y])
    {
        assert(1);
        dd[x]=1;
        return ;
    }
    assert(x!=y);
    par[x]=y;
}
bool dosth(ll x,ll y)
{
    vector<pll> vt;
    vt.pb(make_pair(x,y));
    chk[x][y]=cntnw;
    for (int i=0; i<vt.size(); i++)
    {
        auto p=vt[i];
        int x=p.ff;
        int y=p.ss;
        for (int j=0; j<4; j++)
        {
            int x1=x+ax[j];
            int y1=y+ay[j];

            if (x1>=1&&x1<=n&&y1>=1&&y1<=m&&chk[x1][y1]!=cntnw&&a[x1][y1])
            {
                ll nw=0;
                for (int k=0; k<4; k++)
                {
                    ll x2=x1+ax[k];
                    ll y2=y1+ay[k];
                    if (a[x2][y2]&&x2>=1&&x2<=n&&y2>=1&&y2<=m&&chk[x2][y2]==cntnw)
                        nw+=(1ll<<k);
                }
                if (a[x1][y1]<=msk[nw])
                {
                    if (find_par(hsh(x1,y1))!=find_par(hsh(x,y)))
                    {
                        dsu(find_par(hsh(x,y)),find_par(hsh(x1,y1)));
                        return true;
                    }
                    chk[x1][y1]=cntnw;
                    vt.pb(make_pair(x1,y1));
                }
            }
        }
    }
    dd[hsh(x,y)]=1;
    for (auto to:vt)
    {
        ans[to.ff][to.ss]=vt.size();
    }
    return false;
}
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    if (fopen("t.inp", "r"))
    {
        freopen("test.inp", "r", stdin);
        freopen("test.out", "w", stdout);
    }
    memset(par,-1,sizeof(par));
    memset(ans,0x3f,sizeof(ans));
    cin>>p>> n>> m;
    string s;
    cin>> s;
    for (int i=0; i<p; i++)
    {
        if (s[i]=='N')
            s[i]='0';
        else if (s[i]=='E')
            s[i]='1';
        else if (s[i]=='S')
            s[i]='2';
        else
            s[i]='3';
    }
    for (int i=1; i<=n; i++)
    {
        for (int j=1; j<=m; j++)
        {
            cin>>a[i][j];
        }
    }
    p+=p;
    s+=s;
    for (int i=1; i<16; i++)
    {
        ll pre=-1;
        for (int j=0; j<p; j++)
        {
            ll t=s[j]-'0';
           // cout <<t<<endl;
            if (i&(1ll<<t))
                msk[i]=max(msk[i],j-pre);
            else
                pre=j;
        }
        if (msk[i]==p)
            msk[i]=base;
         //   cout<<msk[i]<<" ";
    }
    //1 2 3 2 2 4 5 1 2 2 4 3 4 5 3000000000000000000
    while (1)
    {
        bool chk=0;
        for (int i=1; i<=n; i++)
        {
            for (int j=1; j<=m; j++)
            {
                if (a[i][j]&&!dd[hsh(i,j)]&&find_par(hsh(i,j))==hsh(i,j))
                {
                    cntnw++;
                    chk|=dosth(i,j);
                }
            }
        }
        if (!chk)
            break;
    }
    pll res=make_pair(base,0);
    for (int i=1; i<=n; i++)
    {
        for (int j=1; j<=m; j++)
        {
            if (!a[i][j])
                continue;
            if (res.ff>ans[i][j])
            {
                res.ff=ans[i][j];
                res.ss=1;
            }
            else if (res.ff==ans[i][j])
                res.ss++;
        }
    }
    cout <<res.ff<<endl;
    cout <<res.ss<<endl;

}

Compilation message (stderr)

virus.cpp: In function 'bool dosth(long long int, long long int)':
virus.cpp:52:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   52 |     for (int i=0; i<vt.size(); i++)
      |                   ~^~~~~~~~~~
virus.cpp: In function 'int main()':
virus.cpp:99:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   99 |         freopen("test.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
virus.cpp:100:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  100 |         freopen("test.out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 14 / 14
• Subtask 2: 6 / 6
• Subtask 3: 80 / 80