Submission #758617

#	Time	Username	Problem	Language	Result	Execution time	Memory
758617		fanwen	Robots (APIO13_robots)	C++17	0 / 100	4 ms	8276 KiB

robots

/**
 *      author : pham van sam
 *      created : 15 June 2023 (Thursday)
 **/

#include <bits/stdc++.h>

using namespace std;
using namespace chrono;

#define MASK(x) (1LL << (x))
#define BIT(x, i) (((x) >> (i)) & 1)
#define ALL(x) (x).begin(), (x).end()
#define REP(i, n) for (int i = 0, _n = n; i < _n; ++i)
#define FOR(i, a, b) for (int i = (a), _b = (b); i <= _b; ++i)
#define FORD(i, a, b) for (int i = (a), _b = (b); i >= _b; --i)
#define FORE(it, s) for (__typeof(s.begin()) it = (s).begin(); it != (s).end(); ++it)

template <typename U, typename V> bool maximize(U &A, const V &B) { return (A < B) ? (A = B, true) : false; }
template <typename U, typename V> bool minimize(U &A, const V &B) { return (A > B) ? (A = B, true) : false; }

const int MAXN = 505;
const int dir[] = {-1, 0, 1, 0, 0, 1, 0, -1};

int N, W, H, dp[2][MAXN][MAXN][4];
vector <pair <int, int>> points;
char a[MAXN][MAXN];

inline bool inside(int x, int y) {
    return (x  > 0 && y > 0 && x <= W && y <= H);
}

namespace sub1 {
    void bfs(int x, int y, int id) {
        queue <array <int, 3>> q;
        memset(dp[id], 0x3f, sizeof dp[id]);
        REP(i, 4) {
            dp[id][x][y][i] = 1;
            q.push({x, y, i});
        }
        while(!q.empty()) {
            auto [u, v, i] = q.front(); q.pop();
            REP(t, 4) {
                int x = u + dir[t];
                int y = v + dir[t + 4];
                if(!inside(x, y)) continue;
                if(a[x][y] == 'x') continue;
                if(minimize(dp[id][x][y][t], dp[id][u][v][i] + (t != i))) {
                    q.push({x, y, t});
                }
            }
        }
    }

    bool check(int i, int j, int t) {
        int x = i + dir[t];
        int y = j + dir[t + 4];
        if(!inside(x, y)) return true;
        return a[x][y] == 'x';
    }

    void Main() {
        bfs(points[0].first, points[0].second, 0);
        bfs(points[1].first, points[1].second, 1);
        int ans = 1e9;
        FOR(i, 1, W) FOR(j, 1, H) {
            REP(t1, 4) {
                REP(t2, 4) {
                    if(check(i, j, t1) || check(i, j, t2)) {
                        minimize(ans, dp[0][i][j][t1] + dp[1][i][j][t2]);
                    }
                }
            }
        }
        if(ans >= 1e9) ans = -1;
        cout << ans; exit(0);
    }
}

void process(void) {
    cin >> N >> H >> W;
    FOR(i, 1, W) FOR(j, 1, H) {
        cin >> a[i][j];
        if(a[i][j] >= '1' && a[i][j] <= '9') points.emplace_back(i, j);
    }
    if(N == 2) sub1::Main();
}

signed main() {

    #define TASK "TASK"
    if(fopen(TASK".inp", "r")) {
        freopen(TASK".inp", "r", stdin);
        freopen(TASK".out", "w", stdout);
    }

    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    auto start_time = steady_clock::now();
    int test = 1;
    // cin >> test;
    for (int i = 1; i <= test; ++i) {
        process();
        // cout << '\n';
    }

    auto end_time = steady_clock::now();

    cerr << "\nExecution time : " << duration_cast<milliseconds> (end_time - start_time).count() << "[ms]" << endl;

    return (0 ^ 0);
}

Compilation message (stderr)

robots.cpp: In function 'int main()':
robots.cpp:93:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   93 |         freopen(TASK".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
robots.cpp:94:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   94 |         freopen(TASK".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 10
• Subtask 2: 0 / 20
• Subtask 3: 0 / 30
• Subtask 4: 0 / 40