Submission #1315696

#	Time	Username	Problem	Language	Result	Execution time	Memory
1315696		the_commando_x	Tracks in the Snow (BOI13_tracks)	C++17	100 / 100	353 ms	89584 KiB

tracks

#include <bits/stdc++.h>

using namespace std;

using vi = vector<int>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;

using pii = pair<int, int>;
using vii = vector<pii>;
using vvii = vector<vii>;

using l = long long;
using vl = vector<l>;
using vvl = vector<vl>;
using vvvl = vector<vvl>;

using pll = pair<l, l>;
using vll = vector<pll>;
using vvll = vector<vll>;

using d = double;
using vd = vector<d>;
using vvd = vector<vd>;
using vvvd = vector<vvd>;

using ld = long double;
using vld = vector<ld>;
using vvld = vector<vld>;
using vvvld = vector<vvld>;

using vb = vector<bool>;
using vvb = vector<vb>;
using pbb = pair<bool, bool>;
using vbb = vector<pbb>;

#define ff first
#define ss second

#define pb push_back
#define eb emplace_back
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define sz(x) (int)(x).size()

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

const ld pi = 3.14159265358979323846;

const l LINF = 1e18;
const l INF = 1e9;

const l MOD = 1e9 + 7;
// const l MOD = 998244353;

const l MAXN = 2e5 + 5;

vi dx = {0, 0, 1, -1};
vi dy = {1, -1, 0, 0};

void solve()
{
    int n, m;
    cin >> n >> m;

    vector<string> a(n);
    for (int i = 0; i < n; ++i)
        cin >> a[i];

    deque<tuple<int, int, int>> q;
    vvb vis(n, vb(m, false));

    q.push_front({0, 0, 0}), vis[0][0] = true;

    int ans = 0;
    while (q.size())
    {
        auto [d, x, y] = q.front();
        q.pop_front();

        ans = max(ans, d);

        for (int i = 0; i < 4; ++i)
        {
            int nx = x + dx[i], ny = y + dy[i];
            if (nx < 0 || nx >= n || ny < 0 || ny >= m || vis[nx][ny])
                continue;
            if (a[nx][ny] == '.')
                continue;

            if (a[nx][ny] == a[x][y])
                q.push_front({d, nx, ny});
            else if (a[nx][ny] != a[x][y])
                q.push_back({d + 1, nx, ny});

            vis[nx][ny] = true;
        }
    }

    cout << ans + 1;
}

int main()
{
    setIO("");

#ifndef ONLINE_JUDGE
    // setIO("filename");
#endif

    int t = 1;
    // cin >> t;
    while (t--)
        solve();

    return 0;
}

Compilation message (stderr)

tracks.cpp: In function 'void setIO(std::string)':
tracks.cpp:52:22: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   52 |         (void)freopen((name + ".in").c_str(), "r", stdin);
      |               ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
tracks.cpp:53:22: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   53 |         (void)freopen((name + ".out").c_str(), "w", stdout);
      |               ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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