Submission #477918

#	Time	Username	Problem	Language	Result	Execution time	Memory
477918		Shogun3103	Tracks in the Snow (BOI13_tracks)	C++17	100 / 100	795 ms	131140 KiB

tracks

#include <bits/stdc++.h>
 
using namespace std;

#define ll long long
#define ld long double
#define FOR(i,a,b) for(__typeof(b) i=a; i<=b; i++)
#define FOD(i,a,b) for(__typeof(b) i=b; i>=a; i--)
#define EACH(u, v) for(auto& u : v)
#define sz(x) ((int)(x).size())
#define all(x) (x).begin(), (x).end()
#define pb push_back
#define pf push_front
#define ii pair<int,int>
#define iii pair<int,ii>
#define f first
#define s second
#define ed "\n"
#define sp " "
#define vi vector<int>
#define vii vector<ii>
#define vl vector<ll>
#define NO cout << "NO" << ed;
#define YES cout << "YES" << ed;
#define no cout << "no" << ed;
#define yes cout << "yes" << ed;

void setIO(string fileName = ""){
    if(fileName.length()){
        freopen((fileName+".in").c_str(), "r", stdin);
        freopen((fileName+".out").c_str(), "w", stdout);
    }
}

const int oo1 = 1e9 + 7;
const int oo2 = 1e9 + 9;
const int d4x[] = {0, 0, 1, -1};
const int d4y[] = {1, -1, 0, 0};
const int d8x[] = {-1, 0, 1, -1, 1, -1, 0, 1};
const int d8y[] = {1, 1, 1, 0, 0, -1, -1, -1};
const int N = 4000 + 10;
const int M = 1e2 + 10;
vi adj[N];

int n, m, dep[N][N];
char a[N][N];

bool ok(int x, int y)
{
    return x && y && x <= n && y <= m && a[x][y] != '.';
}

void solve()
{
    cin >> n >> m;
    FOR(i, 1, n) FOR(j, 1, m) cin >> a[i][j];

    int ans = 0;
    deque<ii> q;
    q.pb({1, 1});
    dep[1][1] = 1;
    while(sz(q)) {
        ii cur = q.front();
        q.pop_front();
        ans = max(ans, dep[cur.f][cur.s]);
        FOR(i, 0, 3) {
            int x = cur.f + d4x[i];
            int y = cur.s + d4y[i];
            if(ok(x, y) && !dep[x][y]) {
                if(a[x][y] == a[cur.f][cur.s]) {
                    dep[x][y] = dep[cur.f][cur.s];
                    q.pf({x, y});
                } else {    
                    dep[x][y] = dep[cur.f][cur.s] + 1;
                    q.pb({x, y});
                }
            }
        }
    }
    cout << ans;
}

int main()
{ 
    ios_base::sync_with_stdio(false), cin.tie(0), cout.tie(0);        
    setIO("");
    int t; t = 1;
    //int t; cin >> t;
    FOR(i, 1, t) {
        solve();
    }
    return 0;
}

Compilation message (stderr)

tracks.cpp: In function 'void setIO(std::string)':
tracks.cpp:30:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   30 |         freopen((fileName+".in").c_str(), "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
tracks.cpp:31:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   31 |         freopen((fileName+".out").c_str(), "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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