Submission #1277392

#	Time	Username	Problem	Language	Result	Execution time	Memory
1277392		shirokito	Dango Maker (JOI18_dango_maker)	C++20	33 / 100	1807 ms	284416 KiB

dango_maker

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

using ll = long long;

const int N = 3000 + 24;

int n, m; char a[N][N]; int idL[N][N], idT[N][N];
vector<vector<int>> g;
int tdfs = 0; vector<int> match, vis;

bool ok(int i, int j, int dir) {
    if (dir == 0) {
        return (j + 2 <= m && a[i][j] == 'R' && a[i][j + 1] == 'G' && a[i][j + 2] == 'W');
    }
    else {
        return (i + 2 <= n && a[i][j] == 'R' && a[i + 1][j] == 'G' && a[i + 2][j] == 'W');
    }
}

bool kuhn(int u) {
    if (vis[u] == tdfs) return 0;
    vis[u] = tdfs;

    for (int v: g[u]) {
        if (match[v] == 0 || kuhn(match[v])) {
            match[v] = u;
            return 1;
        }
    }

    return 0;
}

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

    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= m; j++) {
            cin >> a[i][j];
        }
    }

    int szL = 0, szT = 0;

    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= m; j++) {
            if (ok(i, j, 0)) idL[i][j] = ++szL;
            if (ok(i, j, 1)) idT[i][j] = ++szT;
        }
    }

    g.assign(szL + 1, vector<int>());
    match.resize(szT + 1, 0); vis.resize(szL + 1, 0);

    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= m; j++) {
            if (!ok(i, j, 0)) continue;
            if (ok(i, j, 1)) g[idL[i][j]].push_back(idT[i][j]);
            if (i - 1 >= 1 && j + 1 <= m && ok(i - 1, j + 1, 1)) g[idL[i][j]].push_back(idT[i - 1][j + 1]);
            if (i - 2 >= 1 && j + 2 <= m && ok(i - 2, j + 2, 1)) g[idL[i][j]].push_back(idT[i - 2][j + 2]);
        }
    }

    vector<int> id; for (int i = 1; i <= szL; i++) id.push_back(i);
    random_shuffle(id.begin(), id.end());

    for (int i: id) {
        tdfs++;
        kuhn(i);
    }

    int cnt_match = 0;
    for (int i = 1; i <= szT; i++) {
        if (match[i] != 0) cnt_match++;
    }

    cout << (szL + szT) - cnt_match << '\n';
}   

int main() {
    cin.tie(0) -> sync_with_stdio(0);

    int T = 1; // cin >> T;
    while (T--) {
        solve();
    }
}

Compilation message (stderr)

dango_maker.cpp: In function 'void solve()':
dango_maker.cpp:66:19: warning: 'void std::random_shuffle(_RAIter, _RAIter) [with _RAIter = __gnu_cxx::__normal_iterator<int*, vector<int> >]' is deprecated: use 'std::shuffle' instead [-Wdeprecated-declarations]
   66 |     random_shuffle(id.begin(), id.end());
      |     ~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/13/algorithm:61,
                 from /usr/include/x86_64-linux-gnu/c++/13/bits/stdc++.h:51,
                 from dango_maker.cpp:1:
/usr/include/c++/13/bits/stl_algo.h:4581:5: note: declared here
 4581 |     random_shuffle(_RandomAccessIterator __first, _RandomAccessIterator __last)
      |     ^~~~~~~~~~~~~~

• Subtask 1: 13 / 13
• Subtask 2: 20 / 20
• Subtask 3: 0 / 67