Submission #1094990

#	Time	Username	Problem	Language	Result	Execution time	Memory
1094990		Rafat	Mecho (IOI09_mecho)	C++14	100 / 100	126 ms	7244 KiB

mecho

#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
#include <time.h>
#include <cstdlib>
#include <ctime>
#include <cstdio>
#include <cstring>

using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <iostream>

using namespace __gnu_pbds;
using namespace std;
template <class T>
using Tree =
    tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
// to erase in multiset-> less_equal<T> and 
// s.erase(s.find_by_order(s.order_of_key(x)))
// lower_bound(x)=>(cannot use the stl lower_bound function)
// ll idx = s.order_of_key(x)
// if(idx == s.size()) -> no lower_bound
// else lb = *s.find_by_order(idx) // as 0-indexing
// idx-1 will give highest value which is strictly less than x
// for upper_bound->do the same with (x+1)

typedef long long ll;
typedef long double ld;
typedef pair<int,int> p32;
typedef pair<ll,ll> p64;
typedef tuple<ll, ll, ll> t64;
typedef vector<t64> vt64;
typedef vector<vt64> vvt64;
typedef pair<double,double> pdd;
typedef vector<ll> v64;
typedef vector<int> v32;
typedef vector<vector<int> > vv32;
typedef vector<vector<ll> > vv64;
typedef vector<vector<p64> > vvp64;
typedef vector<p64> vp64;
typedef vector<p32> vp32;
typedef vector<vector<p32> > vvp32;
typedef vector<bool> vb;
ll mod =  1e9+7, MOD = 998244353;
double eps = 1e-12;
// #define forn(i,e) for(ll i = 0; i < e; i++)
#define FOR(s, e, i) for(int i = s; i <= e; i++)
// #define rforn(i,s) for(ll i = s; i >= 0; i--)
#define ROF(s ,e, i) for(int i = s; i >= e; i--)
#define coutAll(A) for(auto asdafas : A) cout <<  asdafas << " "; cout << "\n";
#define foutAll(A) for(auto asdafas : A) fout <<  asdafas << " "; cout << "\n";
#define cinAll(A) for(auto &asdafas : A) cin >>  asdafas;
#define finAll(A) for(auto &asdafas : A) fin >>  asdafas;
#define minpq priority_queue<ll, v64, greater<ll>>
#define maxpq priority_queue<ll> 
#define ln "\n"
#define dbg(x) cout<<#x<<" = "<<x<<ln
#define mp make_pair
#define mt make_tuple
#define pb push_back
#define fi first
#define se second
ll inf = LLONG_MAX;
#define fast_cin() ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL)
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define sz(x) ((ll)(x).size())
#define yes cout<<"YES\n"
#define no cout<<"NO\n"
using namespace std;
typedef long long ll;
typedef vector<ll> vll;
typedef vector<vector<ll>> vvll;
typedef pair<ll, ll> pll;
typedef pair<ll, ll> pii;
//#define MAXN 1000000
struct info{
    int i, j, dist;
    bool isbear;
    // info(int x, int y, bool b) : i(x), j(y), dist(0), isbear(b){}
};
void solve(int it)
{
    ll n, s;
    cin >> n >> s;
    vector<string>A(n);
    cinAll(A);
    int bi, bj, hi, hj;
    vp32 hives;
    queue<p32>q;
    vv32 dist_bee(n, v32(n, 1e9));
    FOR(0, n - 1, i){
        FOR(0, n - 1, j){
            if(A[i][j] == 'D'){
                hi = i;
                hj = j;
                continue;
            }
            if(A[i][j] == 'M'){
                bi = i;
                bj = j;
                continue;
            }
            if(A[i][j] == 'H'){
                hives.emplace_back(i, j);
                q.push({i, j});
                dist_bee[i][j] = 0;
            }
        }
    }
    int dx[] = {1, -1, 0, 0};
    int dy[] = {0, 0, 1, -1};
    while(!q.empty()){
        auto u = q.front();
        q.pop();
        FOR(0, 3, i){
            int ni = u.fi + dx[i];
            int nj = u.se + dy[i];
            if(ni < 0) continue;
            if(nj < 0) continue;
            if(ni > n-1) continue;
            if(nj > n-1) continue;
            if(A[ni][nj] == 'T') continue;
            if(A[ni][nj] == 'D') continue;
            if(dist_bee[ni][nj] != 1e9) continue;
            dist_bee[ni][nj] = dist_bee[u.fi][u.se] + 1;
            q.push({ni, nj});
        }        
    }
    auto ok = [&](ll rest)->bool{
        q.push({bi, bj});
        vv32 dist(n, v32(n, 1e9));
        dist[bi][bj] = 0;
        if(rest >= dist_bee[bi][bj]) return false;
        while(!q.empty()){
            auto u = q.front();
            q.pop();
            FOR(0, 3, i){
                int ni = u.fi + dx[i];
                int nj = u.se + dy[i];
                if(ni < 0) continue;
                if(nj < 0) continue;
                if(ni > n-1) continue;
                if(nj > n-1) continue;
                if(A[ni][nj] == 'T') continue;
                if(dist[ni][nj] != 1e9) continue;
                if((dist[u.fi][u.se] + 1)/s+rest >= dist_bee[ni][nj]) continue;
                if(A[ni][nj] == 'D') return true;
                dist[ni][nj] = dist[u.fi][u.se] + 1;
                q.push({ni, nj});
            }        
        }
        return false;
    };
    int l = 0, r = 1e6, ans = -1;
    while(l <= r){
        ll mid = (l + r) / 2;
        if(ok(mid)){
            ans = mid;
            l = mid + 1;
        }else{
            r = mid - 1;
        }
    }
    cout << ans;
}


int main()
{
    fast_cin();    
    ll t = 1;
    // cin >> t;
    for(int it=1; it<=t; it++)
    {
        //cout << "Case " << it << ": ";
        solve(it);
    }
    return 0;
}

Compilation message (stderr)

mecho.cpp: In function 'void solve(int)':
mecho.cpp:90:17: warning: variable 'hi' set but not used [-Wunused-but-set-variable]
   90 |     int bi, bj, hi, hj;
      |                 ^~
mecho.cpp:90:21: warning: variable 'hj' set but not used [-Wunused-but-set-variable]
   90 |     int bi, bj, hi, hj;
      |                     ^~
mecho.cpp:135:20: warning: 'bj' may be used uninitialized in this function [-Wmaybe-uninitialized]
  135 |         dist[bi][bj] = 0;
      |                    ^
mecho.cpp:135:16: warning: 'bi' may be used uninitialized in this function [-Wmaybe-uninitialized]
  135 |         dist[bi][bj] = 0;
      |                ^

• Subtask 1: 100 / 100