Submission #1161679

#	Time	Username	Problem	Language	Result	Execution time	Memory
1161679		Madhav_1608	Tracks in the Snow (BOI13_tracks)	C++20	82.50 / 100	2097 ms	178468 KiB

tracks

#include <iostream>
#include <stack>
#include <queue>
#include <string>
#include <algorithm>
#include <vector>
#include <map>
#include <set>
#include <climits>
#include <cmath>
#include <unordered_map>
#include <unordered_set>
#include <numeric>
#include <iomanip>
#include <cstring>
#include <stdio.h>
#include <assert.h>
using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef vector<string> vs;
typedef vector<long long> vll;
typedef pair<ll,ll> pll;
#define double long double
const double eps = 1e-9; 
#define FOR(i,a,b) for(long long i=a;i<b;i++)
#define all(v) v.begin(),v.end()
template <typename I>
void print(vector<I> &v){
    FOR(i,0,v.size()){cout << v[i] << " ";}
    cout << "\n";
}
ll gcd(ll a,ll b){
    if(a==0){return b;}
    else if(b==0){return a;}
    else if(a<b){return gcd(b%a,a);}
    else{return gcd(a%b,b);}
}
ll lcm(ll a,ll b){
    return (a/gcd(a,b))*b;
}
void setIO(string name = "") {
    freopen((name + ".in").c_str(), "r", stdin); // see /general/input-output
    freopen((name + ".out").c_str(), "w", stdout);
}
void init_code(){
    #ifndef ONLINE_JUDGE
    freopen("input.txt","r",stdin);
    freopen("output.txt","w",stdout);
    #endif
}
void solve(){
    // store very big numbers may mean log2
    ll h,w;
    cin >> h >> w;
    vector<string> meadow(h);
    FOR(i,0,h) cin >> meadow[i];
    vector<bool> visited(h*w,false);
    vll dist(h*w,INT_MAX);
    priority_queue<pll,vector<pll>,greater<pll>> pq;
    pq.push({1,0});
    dist[0] = 1;
    while(!pq.empty()){
        pll curr = pq.top();
        pq.pop();
        if(visited[curr.second]) continue;
        dist[curr.second] = curr.first;
        visited[curr.second] = true;
        ll r = curr.second/w;
        ll c = curr.second%w;
        if(c>0){
            if(meadow[r][c-1]!='.'){
                if(meadow[r][c-1]==meadow[r][c]){
                    pq.push({curr.first,curr.second-1});
                }
                else{
                    pq.push({curr.first+1,curr.second-1});
                }
            }
        }
        if(c<(w-1)){
            if(meadow[r][c+1]!='.'){
                if(meadow[r][c+1]==meadow[r][c]){
                    pq.push({curr.first,curr.second+1});
                }
                else{
                    pq.push({curr.first+1,curr.second+1});
                }
            }            
        }
        if(r>0){
            if(meadow[r-1][c]!='.'){
                if(meadow[r-1][c]==meadow[r][c]){
                    pq.push({curr.first,curr.second-w});
                }
                else{
                    pq.push({curr.first+1,curr.second-w});
                }
            }
        }
        if(r<(h-1)){
            if(meadow[r+1][c]!='.'){
                if(meadow[r+1][c]==meadow[r][c]){
                    pq.push({curr.first,curr.second+w});
                }
                else{
                    pq.push({curr.first+1,curr.second+w});
                }
            }            
        }
    }
    ll ans = 0;
    FOR(i,0,h*w){
        if(dist[i]<INT_MAX) ans = max(ans,dist[i]);
    }
    cout << ans << "\n";
}

signed main(){
    //setIO
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    // init_code();
    ll t=1;
    // cin >> t;
    while(t--){
        solve();
    }
    return 0;
}

Compilation message (stderr)

tracks.cpp: In function 'void setIO(std::string)':
tracks.cpp:43:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   43 |     freopen((name + ".in").c_str(), "r", stdin); // see /general/input-output
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
tracks.cpp:44:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   44 |     freopen((name + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
tracks.cpp: In function 'void init_code()':
tracks.cpp:48:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   48 |     freopen("input.txt","r",stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
tracks.cpp:49:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   49 |     freopen("output.txt","w",stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 30 / 30
• Subtask 2: 52.5 / 70