Submission #442178

#	Time	Username	Problem	Language	Result	Execution time	Memory
442178		Haidara	Mecho (IOI09_mecho)	C++17	20 / 100	391 ms	12084 KiB

mecho

/* * * * * * * * * *\
 * Author: Haidara *
 * LANG: C++17     *
 * PROB:           *
\* * * * * * * * * */
#include<bits/stdc++.h>
#define fast ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
#define int long long
#define rep(i,x,n) for(int i=x;i<(n);i++)
#define FOR(i,n) rep(i,0,n)
#define per(i,x,n) for(int i=x;i>(n);i--)
#define ROF(i,x) for(int i=x;i>=0;i--)
#define v(i) vector< i >
#define p(i,j) pair< i , j >
#define pii pair<int,int>
#define m(i,j) map< i , j >
#define um(i,j) unordered_map< i , j >
#define pq(i) priority_queue< i >
#define ff first
#define all(x) x.begin(),x.end()
#define ss second
#define pp push_back
using namespace std;
void SIO(string name="")
{
    if(name!="")
    {
        freopen((name+".in").c_str(),"r",stdin);
        freopen((name+".out").c_str(),"w",stdout);
    }
}
const int inf=1LL<<60LL;
const int mod=1e9+7;
const int maxn=808;
int n,foot;
pii Mecho,House;
char a[maxn][maxn];
bool vis[maxn][maxn];
queue<pii>q;
v(v(int)) dist;
int dx[] {-1,1,0,0};
int dy[] {0,0,-1,1};
bool valid(int x,int y)
{
    return x>=0&&y>=0&&x<n&&y<n&&a[x][y]=='G';
}
bool nvalid(int x,int y)
{
    return x>=0&&y>=0&&x<n&&y<n;
}
bool check(int Time)
{
    v(v(int))newdist;
    newdist=dist;
    FOR(i,maxn)
    FOR(j,maxn)
    {
        vis[i][j]=0;
        if(a[i][j]=='T'||a[i][j]=='H'||a[i][j]=='M')
            vis[i][j]=1;
    }
    queue<p(pii,int)>nq;
    nq.push({Mecho,foot});
    newdist[Mecho.ff][Mecho.ss]=Time;
    while(nq.size())
    {
        pii f=nq.front().ff;
        int lft=nq.front().ss;
        nq.pop();
        FOR(i,4)
        {
            int x=f.ff+dx[i],y=f.ss+dy[i];
            if(nvalid(x,y)&&(a[x][y]=='G'||a[x][y]=='D'))
            {
                if(!vis[x][y])
                {
                    if(lft)
                    {
                        if(newdist[x][y]>newdist[f.ff][f.ss])
                        {
                            newdist[x][y]=newdist[f.ff][f.ss];
                            nq.push({{x,y},lft-1});
                            vis[x][y]=1;
                        }
                    }
                    else
                    {
                        if(newdist[x][y]>newdist[f.ff][f.ss]+1)
                        {
                            newdist[x][y]=newdist[f.ff][f.ss];
                            nq.push({{x,y},foot});
                            vis[x][y]=1;
                        }
                    }
                }
            }
        }
    }
    return newdist[House.ff][House.ss]!=inf;
}
void solve()
{
    while(q.size())
    {
        pii f=q.front();
        q.pop();
        FOR(i,4)
        {
            int x=f.ff+dx[i],y=f.ss+dy[i];
            if(valid(x,y))
            {
                if(!vis[x][y])
                {
                    vis[x][y]=1;
                    q.push({x,y});
                    dist[x][y]=dist[f.ff][f.ss]+1;
                }
                else if(dist[x][y]>dist[f.ff][f.ss]+1)
                {
                    dist[x][y]=dist[f.ff][f.ss]+1;
                    q.push({x,y});
                }
            }
        }
    }
}
signed main()
{
    SIO("");
    cin>>n>>foot;
    dist.resize(maxn);
    FOR(i,maxn)
    dist[i].resize(maxn);
    FOR(i,n)
    FOR(j,n)
    {
        cin>>a[i][j];
        dist[i][j]=inf;
        if(a[i][j]=='M')
            Mecho= {i,j};
        else if(a[i][j]=='H')
            q.push({i,j}),vis[i][j]=1,dist[i][j]=0;
        else if(a[i][j]=='T')
            vis[i][j]=1;
        else if(a[i][j]=='D')
        House={i,j};
    }
    solve();
    int l=1,r=800*800,ans=-1;
    while(l<=r)
    {
        int mid=l+(r-l)/2;
        if(check(mid))
            ans=max(ans,mid-1),l=mid+1;
        else
            r=mid-1;
    }
    cout<<ans;
}

Compilation message (stderr)

mecho.cpp: In function 'void SIO(std::string)':
mecho.cpp:28:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   28 |         freopen((name+".in").c_str(),"r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mecho.cpp:29:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   29 |         freopen((name+".out").c_str(),"w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 20 / 100