Submission #57587

#	Time	Username	Problem	Language	Result	Execution time	Memory
57587		Bodo171	Mecho (IOI09_mecho)	C++14	100 / 100	363 ms	10748 KiB

mecho

#include <iostream>
#include <fstream>

using namespace std;
const int nmax=805;
int d1[]={-1,0,1,0};
int d2[]={0,-1,0,1};
int d[nmax][nmax],a[nmax][nmax];
string s;
pair<int,int> q[nmax*nmax];
int p,u,n,m,i,j,li,ci,lf,cf,l1,l2,c1,c2,S,ans;
bool ok(int X,int Y)
{
    return (X>=1&&Y>=1&&X<=n&&Y<=n);
}
void bfs()
{
    p=1;
    for(i=1;i<=n;i++)
        for(j=1;j<=n;j++)
           if(a[i][j]==0)
             q[++u]={i,j};
    for(p=1;p<=u;p++)
    {
        li=q[p].first;ci=q[p].second;
        for(i=0;i<4;i++)
        {
            lf=li+d1[i];cf=ci+d2[i];
            if(ok(lf,cf)&&a[li][ci]+1<a[lf][cf])
            {
                a[lf][cf]=a[li][ci]+1;
                q[++u]={lf,cf};
            }
        }
    }

}
bool check(int val)
{
    for(i=1;i<=n;i++)
        for(j=1;j<=n;j++)
           if(d[i][j]!=-1)
              d[i][j]=0;
    d[l1][c1]=1;
    q[p=u=1]={l1,c1};
    for(p=1;p<=u;p++)
    {
        li=q[p].first;ci=q[p].second;
        if(li==l2&&ci==c2) return 1;
        if((d[li][ci]-1)/S+val>=a[li][ci]) continue;
        for(i=0;i<4;i++)
        {
            lf=li+d1[i];cf=ci+d2[i];
            if(ok(lf,cf)&&(!d[lf][cf]))
            {
                d[lf][cf]=d[li][ci]+1;
                q[++u]={lf,cf};
            }
        }
    }
    return 0;
}
int main()
{
    //freopen("data.in","r",stdin);
    cin>>n>>S;
    for(i=0;i<=n+1;i++)
        for(j=0;j<=n+1;j++)
           a[i][j]=(1<<30);
    for(i=1;i<=n;i++)
    {
        cin>>s;
        for(j=0;j<n;j++)
        {
            if(s[j]=='T') d[i][j+1]=a[i][j+1]=-1;
            if(s[j]=='M') l1=i,c1=j+1;
            if(s[j]=='D') l2=i,c2=j+1,a[i][j+1]=-1;
            if(s[j]=='H') a[i][j+1]=0;
        }
    }
    bfs();
   for(int pu=20;pu>=0;pu--)
        if(check(ans+(1<<pu)))
           ans+=(1<<pu);
    if(!check(0)) ans=-1;
    cout<<ans;
    return 0;
}

• Subtask 1: 100 / 100