Submission #472735

#	Time	Username	Problem	Language	Result	Execution time	Memory
472735		hackerbhaiya	Mecho (IOI09_mecho)	C++17	95 / 100	561 ms	11304 KiB

mecho

#include<bits/stdc++.h>
// #pragma GCC optimize("Ofast")
// #pragma GCC target("avx,avx2,fma")
// #pragma GCC optimization("unroll-loops")
// #pragma GCC optimize("unroll-loops")
// #pragma GCC optimize("fast-math")
// #pragma GCC optimize("no-stack-protector")
// #define ll __int128
#define ll long long
// #define ll int
#define f(i,a,b) for(int i=a;i<b;i++)
#define mod 1000000007
// #define mod 998244353 
#define mp make_pair
#define uniq(v) (v).erase(unique(all(v)),(v).end())
#define ff first
#define ss second
#define rf(i,a,b) for(int i=a;i>=b;i--)
#define sc(a) scanf("%lld",&a)
#define pf printf
#define sz(a) (int)(a.size())
#define psf push_front
#define ppf pop_front
#define ppb pop_back
#define pb push_back
#define pq priority_queue
#define all(s) s.begin(),s.end()
#define sp(a) setprecision(a)
#define rz resize
#define ld long double
#define inf (ll)1e18
#define ub upper_bound
#define lb lower_bound
#define bs binary_search
#define eb emplace_back
const double pi = acos(-1);
ll binpow(ll a, ll b){ll res=1;while(b!=0){if(b&1)res*=a;a*=a;b>>=1;}return res;}
// ll binpow(ll a, ll b, ll md){ll res=1;a%=mod;while(b!=0){if(b&1)res*=a,res%=md;a*=a,a%=md;b>>=1;}return res%md;}
 
using namespace std;

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    // freopen("xortransform.in","r",stdin);
    // freopen("xortransform.out","w",stdout);
// #ifndef ONLINE_JUDGE
//     freopen("input.txt","r",stdin);
//     freopen("output.txt","w",stdout);
// #endif
    int z=1;
    // cin>>z;
    f(i,1,z+1)
    {
        //cout<<"Case #"<<i<<": ";
        ll n,d,sx,sy,fx,fy;
        int dx[]={0,1,0,-1};
        int dy[]={1,0,-1,0};
        cin>>n>>d;
        vector<string> s(n);
        f(i,0,n)
            cin>>s[i];
        ll l=0,r=n*n+1;
        queue<vector<ll> > q;
        vector<vector<ll> > dis(n,vector<ll> (n,inf));
        f(i,0,n)
        {
            f(j,0,n)
            {
                if(s[i][j]=='H')
                    q.push({i,j}),dis[i][j]=0;
                else if(s[i][j]=='M')
                    sx=i,sy=j;
                else if(s[i][j]=='D')
                    fx=i,fy=j;
            }
        }
        while(!q.empty())
        {
            auto temp=q.front();
            q.pop();
            ll x=temp[0],y=temp[1];
            f(i,0,4)
            {
                ll xx=x+dx[i],yy=y+dy[i];
                if(xx>=0 && yy>=0 && xx<n && yy<n && s[xx][yy]!='T' && dis[xx][yy]>d+dis[x][y])
                    dis[xx][yy]=d+dis[x][y],q.push({xx,yy});             
            }
        }
        while(l<=r)
        {
            ll mid=(l+r)/2;
            queue<vector<ll> > q;
            vector<vector<ll> > dis2(n,vector<ll> (n,inf));
            if(dis[sx][sy]>mid*d)
                q.push({sx,sy});
            dis2[sx][sy]=mid*d;
            while(!q.empty())
            {
                auto temp=q.front();
                q.pop();
                ll x=temp[0],y=temp[1];
                if(x==fx && y==fy)
                    break;
                f(i,0,4)
                {
                    ll xx=x+dx[i],yy=y+dy[i];
                    if(xx>=0 && yy>=0 && xx<n && yy<n && s[xx][yy]!='T' && dis2[xx][yy]>1+dis2[x][y])
                    {
                        if((xx==fx && yy==fy) || (1+dis2[x][y]<dis[xx][yy]))
                            dis2[xx][yy]=1+dis2[x][y],q.push({xx,yy});       
                    }
                }
            }
            if(dis2[fx][fy]<inf)
                l=mid+1;
            else
                r=mid-1;
        }
        cout<<r<<"\n";
    }
} 

Compilation message (stderr)

mecho.cpp: In function 'int main()':
mecho.cpp:116:27: warning: 'fy' may be used uninitialized in this function [-Wmaybe-uninitialized]
  116 |             if(dis2[fx][fy]<inf)
      |                           ^
mecho.cpp:116:23: warning: 'fx' may be used uninitialized in this function [-Wmaybe-uninitialized]
  116 |             if(dis2[fx][fy]<inf)
      |                       ^
mecho.cpp:96:26: warning: 'sy' may be used uninitialized in this function [-Wmaybe-uninitialized]
   96 |             if(dis[sx][sy]>mid*d)
      |                          ^
mecho.cpp:96:22: warning: 'sx' may be used uninitialized in this function [-Wmaybe-uninitialized]
   96 |             if(dis[sx][sy]>mid*d)
      |                      ^

• Subtask 1: 95 / 100