Submission #1277358

#	Time	Username	Problem	Language	Result	Execution time	Memory
1277358		shirokito	Dango Maker (JOI18_dango_maker)	C++20	33 / 100	1059 ms	318096 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]; bool ok[N][N][2];
vector<int> g[N * N];
int tdfs = 0; int match[N * N], vis[N * N];

int id(int i, int j) {
    return (i - 1) * m + j;
}

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 cnt_node = 0;

    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= m; j++) {
            if (j + 2 <= m && a[i][j] == 'R' && a[i][j + 1] == 'G' && a[i][j + 2] == 'W') {
                ok[i][j][0] = 1;
                cnt_node++;
            }
            if (i + 2 <= n && a[i][j] == 'R' && a[i + 1][j] == 'G' && a[i + 2][j] == 'W') {
                ok[i][j][1] = 1;
                cnt_node++;
            }
        }
    }

    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[id(i, j)].push_back(id(i, j));
            if (i - 1 >= 1 && j + 1 <= m && ok[i - 1][j + 1][1]) g[id(i, j)].push_back(id(i - 1, j + 1));
            if (i - 2 >= 1 && j + 1 <= m && ok[i - 2][j + 2][1]) g[id(i, j)].push_back(id(i - 2, j + 2));
        }
    }

    vector<int> id; for (int i = 1; i <= n * m; 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 <= n * m; i++) {
        if (match[i] != 0) cnt_match++;
    }

    cout << cnt_node - 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:64:19: warning: 'void std::random_shuffle(_RAIter, _RAIter) [with _RAIter = __gnu_cxx::__normal_iterator<int*, vector<int> >]' is deprecated: use 'std::shuffle' instead [-Wdeprecated-declarations]
   64 |     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