Submission #442338

#	Time	Username	Problem	Language	Result	Execution time	Memory
442338		Haidara	Mecho (IOI09_mecho)	C++17	79 / 100	220 ms	7184 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<<62LL;
const int mod=1e9+7;
const int maxn=808;
char a[maxn][maxn];
int n,jump;
pii M,D;
int dist[maxn][maxn],dx[] {-1,1,0,0},dy[] {0,0,1,-1};
bool valid(int x,int y)
{
    return x>=0&&y>=0&&x<n&&y<n&&a[x][y]!='T'&&a[x][y]!='H';
}
bool check(int st)
{
    queue<p(pii,int)>q;
    if(st*jump>=dist[M.ff][M.ss])
        return 0;
    q.push({M,st*jump});
    bool vis[maxn][maxn];
    FOR(i,maxn)
    FOR(j,maxn)
    vis[i][j]=0;
    vis[M.ff][M.ss]=1;
    while(q.size())
    {
        pii f=q.front().ff;
        int curr=q.front().ss;
        q.pop();
        if(f==D)
            return 1;
        FOR(i,4)
        {
            int x=f.ff+dx[i],y=f.ss+dy[i];
            if(!valid(x,y)||dist[x][y]<=curr+1||vis[x][y])
                continue;
            q.push({{x,y},curr+1}),vis[x][y]=1;
        }
    }
    return 0;
}
signed main()
{
    SIO("");
    cin>>n>>jump;
    queue<pii>q;
    FOR(i,n)
    {
        cin>>ws;
        FOR(j,n)
        {
            dist[i][j]=inf;
            cin>>a[i][j];
            if(a[i][j]=='M')
                M= {i,j},a[i][j]='G';
            else if(a[i][j]=='D')
                D= {i,j};
            else if(a[i][j]=='H')
                q.push({i,j}),dist[i][j]=0;
        }
    }
    while(q.size())
    {
        pii f=q.front();
        q.pop();
        FOR(i,4)
        {
            int x=f.ff+dx[i],y=f.ss+dy[i];
            if(x>=0&&y>=0&&x<n&&y<n&&a[x][y]=='G'&&dist[x][y]==inf)
                dist[x][y]=dist[f.ff][f.ss]+jump,q.push({x,y});
        }
    }
    int l=1,r=maxn*maxn*2,ans=-1;
    while(l<=r)
    {
        int mid=l+(r-l)/2;
        if(check(mid))
            ans=max(ans,mid),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: 79 / 100