oj.uz

Submission #1119440

# Submission time Handle Problem Language Result Execution time Memory
1119440 2024-11-27T03:46:37 Z CowTheCow Tracks in the Snow (BOI13_tracks) C++14
100 / 100
 1507 ms 898708 KB 
#pragma GCC optimize("O3")

#include <bits/stdc++.h>

using namespace std;

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
template <typename T>
using ordered_set = tree<T, null_type, less_equal<T>, rb_tree_tag, tree_order_statistics_node_update>;

#include <iostream>
#include <stack>
#include <fstream>
#include <cstdio>
#include <numeric>
#include <time.h>
#include <sys/timeb.h>

#define double long double
#define vi vector<int>
#define pb push_back
#define ll long long
#define ld long double
#define fi first
#define se second
#define pii pair<int,int>
#define sz(a) (int)a.size()
#define revall(a) a.rbegin(), a.rend()
#define all(a) a.begin(),a.end()
#define int_max INT64_MAX/2
#define int_min INT64_MIN/2
#define multierase (a, x) a.erase(a.find(x))
#define pq priority_queue
#define pqr priority_queue<int, vector<int>, greater<int>>
#define contains (a, x) a.find(x)!=a.end()

#define MOD 1000000007
#define SMOD 998244353
#define ODDMOD 100000000

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());

void setIO(string name = ""){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    if (!name.empty()) {
        freopen((name + ".in").c_str(), "r", stdin);
        freopen((name + ".out").c_str(), "w", stdout);
    }
}

void read(vi& arr, int n) {
    for(int i=0;i<n;i++){
        int a;
        cin>>a;
        arr.pb(a);
    } 
}

void print(pii p) {
    cout<<"[ "<<p.first<<" "<<p.second<<" ]"<<endl;
}

void print(vi arr) {
    for(int i : arr) {
        if(i==int_max)
            cout<<"i ";
        else if(i==int_min)
            cout<<"-i ";
        else
            cout<<i<<" ";
    }
    cout<<endl;
}

int ceil_div(int a, int b) {
    if(a%b==0) {
        return a/b;
    }else {
        return (a/b)+1;
    }
}

int h,w;
vector<string> grid;
vector<vi> rep;

void ff(int x, int y, int crep, char gval) {
    if(x<0||y<0||x>=w||y>=h) return;
    if(grid[y][x]!=gval) return;
    if(rep[y][x]!=0) return;

    rep[y][x]=crep;
    ff(x-1, y, crep,gval);
    ff(x+1, y, crep,gval);
    ff(x,y+1,crep,gval);
    ff(x,y-1,crep,gval);
}   

void solve() {
    cin>>h>>w;

    grid.clear();
    for(int i=0;i<h;i++) {
        string s;
        cin>>s;
        grid.pb(s);
    }

    rep=vector<vi>(h, vi(w, 0));

    int crep=1;
    for(int i=0;i<h;i++) {
        for(int j=0;j<w;j++) {
            if(rep[i][j]==0&&grid[i][j]!='.') {
                ff(j,i,crep, grid[i][j]);
                crep++;
            }
        }
    }

    vector<vi> adj;
    adj.resize(crep);

    for(int i=0;i<h;i++) {
        for(int j=0;j<w;j++) {
            if(i!=(h-1)&&rep[i][j]!=0&&rep[i+1][j]!=0) {
                adj[rep[i][j]].pb(rep[i+1][j]);
                adj[rep[i+1][j]].pb(rep[i][j]);
            }
            
            if(j!=(w-1)&&rep[i][j]!=0&&rep[i][j+1]!=0) {
                adj[rep[i][j]].pb(rep[i][j+1]);
                adj[rep[i][j+1]].pb(rep[i][j]);
            }
        }
    }

    vi dist (crep, INT32_MAX);
    vi vis (crep, 0);

    priority_queue<pii> Q;
    Q.push({0, 1});
    dist[1]=0;

    while(!Q.empty()) {
        pii c=Q.top();
        Q.pop();

        if(vis[c.se]) continue;
        vis[c.se]=1;

        for(int i:adj[c.se]) {
            if(dist[i]>dist[c.se]+1) {
                dist[i]=dist[c.se]+1;
                Q.push({-dist[i], i});
            }
        }
    }
    
    int res=0;
    for(int i=1;i<crep;i++) {
        res=max(res, dist[i]);
    }
    cout<<res+1<<endl;
}

signed main() {
    cin.tie(0)->sync_with_stdio(0);
    
    // int x;
    // cin>>x;

    // while(x>0) {
        solve();  
    //     x--;
    // }
}

Compilation message

tracks.cpp: In function 'void setIO(std::string)':
tracks.cpp:49:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   49 |         freopen((name + ".in").c_str(), "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
tracks.cpp:50:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   50 |         freopen((name + ".out").c_str(), "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 27 ms 8272 KB Output is correct
2 Correct 1 ms 336 KB Output is correct
3 Correct 1 ms 336 KB Output is correct
4 Correct 11 ms 4424 KB Output is correct
5 Correct 5 ms 1360 KB Output is correct
6 Correct 1 ms 336 KB Output is correct
7 Correct 1 ms 336 KB Output is correct
8 Correct 1 ms 592 KB Output is correct
9 Correct 1 ms 336 KB Output is correct
10 Correct 4 ms 1616 KB Output is correct
11 Correct 4 ms 1756 KB Output is correct
12 Correct 14 ms 3152 KB Output is correct
13 Correct 5 ms 1360 KB Output is correct
14 Correct 5 ms 1360 KB Output is correct
15 Correct 29 ms 6880 KB Output is correct
16 Correct 26 ms 8272 KB Output is correct
17 Correct 17 ms 4944 KB Output is correct
18 Correct 11 ms 4488 KB Output is correct

Subtask #2
70.0 / 70.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 1360 KB Output is correct
2 Correct 129 ms 28500 KB Output is correct
3 Correct 600 ms 203112 KB Output is correct
4 Correct 162 ms 38204 KB Output is correct
5 Correct 671 ms 326332 KB Output is correct
6 Correct 1328 ms 442268 KB Output is correct
7 Correct 3 ms 1360 KB Output is correct
8 Correct 3 ms 1360 KB Output is correct
9 Correct 4 ms 1616 KB Output is correct
10 Correct 1 ms 848 KB Output is correct
11 Correct 2 ms 1104 KB Output is correct
12 Correct 2 ms 1184 KB Output is correct
13 Correct 110 ms 28488 KB Output is correct
14 Correct 67 ms 16720 KB Output is correct
15 Correct 54 ms 15272 KB Output is correct
16 Correct 62 ms 14160 KB Output is correct
17 Correct 312 ms 72008 KB Output is correct
18 Correct 263 ms 58188 KB Output is correct
19 Correct 157 ms 38216 KB Output is correct
20 Correct 140 ms 46152 KB Output is correct
21 Correct 357 ms 120392 KB Output is correct
22 Correct 681 ms 326412 KB Output is correct
23 Correct 536 ms 139488 KB Output is correct
24 Correct 364 ms 148416 KB Output is correct
25 Correct 1141 ms 235924 KB Output is correct
26 Correct 1425 ms 898708 KB Output is correct
27 Correct 1217 ms 621184 KB Output is correct
28 Correct 1348 ms 446828 KB Output is correct
29 Correct 1263 ms 401332 KB Output is correct
30 Correct 1220 ms 441104 KB Output is correct
31 Correct 1507 ms 332560 KB Output is correct
32 Correct 1043 ms 522928 KB Output is correct