제출 #1305635

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1305635		tkvinhtruongquang	Tracks in the Snow (BOI13_tracks)	C++20	100 / 100	620 ms	160864 KiB

tracks

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

#define fi first
#define se second
#define pb push_back
#define pf push_front
#define sz(x) int(x.size())
#define all(x) x.begin(), x.end()
#define clz __builtin_clz
#define popcount __builtin_popcount
#define lb(x) lower_bound(x)
#define ub(x) upper_bound(x)
#define loop(i, j, n, k) for(int i = j; i <= n; i += k)
#define fast ios_base :: sync_with_stdio(0); cin.tie(0); cout.tie(0)

template <typename T>
inline void print(T x) { cerr << x << endl; }
template <typename T>
inline void print(vector <T> x) { cerr << '['; loop(i, 0, sz(x) - 2, 1) cerr << x[i] << ", "; cerr << x.back() << ']' << endl; }
template <typename T>
inline bool maximize(T &a, const T &b) { return a < b ? (a = b) : 0; }
template <typename T>
inline bool minimize(T &a, const T &b) { return a > b ? (a = b) : 0; }

using ll = long long;
using vi = vector<int>;
using pii = pair<int, int>;
using pss = pair<string, string>;
using vll = vector<ll>;
using pll = pair<ll, ll>;

#define debug(x) cerr << #x << " = "; print(x)

mt19937 rng(chrono :: steady_clock :: now().time_since_epoch().count());
template <typename T>
inline int rand_range(T l, T r) { return uniform_int_distribution<T> (l, r)(rng); }

void setIO(string s) {
    freopen((s + ".in").c_str(), "r", stdin);
    freopen((s + ".out").c_str(), "w", stdout);
    freopen("error.txt", "w", stderr);
}

int dx[] = {1, 0, -1, 0};
int dy[] = {0, 1, 0, -1};

int main() {
    // setIO("task");

    fast;
    int n, m; cin >> n >> m;

    vector<vi> matrix(n + 5, vi(m + 5, 0));

    loop(i, 1, n, 1) {
        loop(j, 1, m, 1) {
            char c; cin >> c;
            if(c == 'R') matrix[i][j] = 1;
            else if(c == 'F') matrix[i][j] = 2;
        }
    }

    if(matrix[1][1] == 0) {
        return cout << 0, 0;
    }

    auto valid = [&](int x, int y) -> bool {
        return x <= n && y <= m && matrix[x][y] > 0;
    };

    vector<vi> dist(n + 5, vi(m + 5, 0));
    deque<pii> dq;
    dq.pb({1, 1});
    dist[1][1] = 1;
    int ans = 0;

    // debug(matrix[3][1]); cerr << endl;

    while(sz(dq)) {
        auto [x, y] = dq.front();
        // debug(x); debug(y); cerr << endl;

        dq.pop_front();

        ans = max(ans, dist[x][y]);
        
        loop(i, 0, 3, 1) {
            int nx = x + dx[i];
            int ny = y + dy[i];

            if(valid(nx, ny) && !dist[nx][ny]) {
                if(matrix[nx][ny] == matrix[x][y]) {
                    dist[nx][ny] = dist[x][y];
                    dq.pf({nx, ny});
                } else {
                    dist[nx][ny] = dist[x][y] + 1;
                    dq.pb({nx, ny});
                }
            }
        }
    }

    cout << ans;
}

컴파일 시 표준 에러 (stderr) 메시지

tracks.cpp: In function 'void setIO(std::string)':
tracks.cpp:40:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   40 |     freopen((s + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
tracks.cpp:41:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   41 |     freopen((s + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
tracks.cpp:42:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   42 |     freopen("error.txt", "w", stderr);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

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