Submission #758799

#	Time	Username	Problem	Language	Result	Execution time	Memory
758799		fanwen	Robots (APIO13_robots)	C++17	100 / 100	330 ms	146888 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, INF = MAXN * MAXN;
const int dir[] = {-1, 0, 1, 0, 0, 1, 0, -1};


int N, Row, Col, dp[10][10][MAXN][MAXN];
string a[MAXN];
pair <int, int> nxt[MAXN][MAXN][4];
vector <pair <int, int>> q[INF];

bool inside(int x, int y) {
    return x >= 0 && x < Row && y >= 0 && y < Col;
}

pair <int, int> end_point(int x, int y, int d) {
    pair <int, int> &cur = nxt[x][y][d];
    if(cur.first != -1) return cur;
    int u = x + dir[d], v = y + dir[d + 4];
    if(!inside(u, v)) return cur = make_pair(x, y);
    if(a[u][v] == 'x') return cur = make_pair(x, y);

    if(a[u][v] == 'A') d = (d + 3) % 4;
    if(a[u][v] == 'C') d = (d + 1) % 4;
    
    return cur = end_point(u, v, d);
}

void process(void) {
    cin >> N >> Col >> Row;
    REP(i, Row) cin >> a[i];
    memset(dp, 0x3f, sizeof dp);

    REP(i, Row) REP(j, Col) if(a[i][j] >= '1' && a[i][j] <= '9') {
        dp[a[i][j] - '0' - 1][a[i][j] - '0' - 1][i][j] = 0;
    }
    REP(i, Row) REP(j, Col) REP(d, 4) {
        nxt[i][j][d] = make_pair(-1, -1);
    }

    REP(rng, N) {
        FOR(l, 0, N - rng - 1) {
            int r = l + rng;
            FOR(t, l, r - 1) REP(i, Row) REP(j, Col) if(a[i][j] != 'x') {
                minimize(dp[l][r][i][j], dp[l][t][i][j] + dp[t + 1][r][i][j]);
            }
        }
        FOR(l, 0, N - rng - 1) {
            int r = l + rng;
            REP(i, Row) REP(j, Col) if(a[i][j] != 'x') {
                if(dp[l][r][i][j] < INF) q[dp[l][r][i][j]].emplace_back(i, j);
            }
            FOR(i, 0, Row * Col) {
                for (auto [x, y] : q[i]) {
                    if(dp[l][r][x][y] != i) continue;
                    REP(d, 4) {
                        auto [nx, ny] = end_point(x, y, d);
                        if(minimize(dp[l][r][nx][ny], dp[l][r][x][y] + 1)) {
                            q[dp[l][r][nx][ny]].emplace_back(nx, ny);
                        }
                    }
                }
                q[i].clear();
            }
        }
    }
    int res = INF;
    REP(i, Row) REP(j, Col) minimize(res, dp[0][N - 1][i][j]);
    // REP(i, Row) REP(j, Col) cout << dp[1][1][i][j] << " \n"[j == Col - 1];
    cout << (res >= INF ? -1 : res) ;
}

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:96:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   96 |         freopen(TASK".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
robots.cpp:97:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   97 |         freopen(TASK".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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