Submission #871682

#	Time	Username	Problem	Language	Result	Execution time	Memory
871682		vjudge1	Zoo (COCI19_zoo)	C++17	0 / 110	12 ms	53596 KiB

zoo

//author: Ahmet Alp Orakci
#include <bits/stdc++.h>
using namespace std;
using i64 = long long;

char matrix[1005][1005];
int vis[1005 * 1005];
set <int> adj[1005 * 1005];
int comp[1005 * 1005];

int dx[4] = {0, 1, 0, -1};
int dy[4] = {-1, 0, 1, 0};

struct DSU {
    int n;
    vector <int> par;
    DSU(int n) : n(n) {
        par.resize(n);
        iota(par.begin(), par.end(), 0);
    }

    inline int get(int x) {
        return par[x] = (x == par[x] ? x : get(par[x]));
    }

    bool same(int a, int b) {
        return get(a) == get(b);
    }

    bool unite(int u, int v) {
        if(same(u, v))
            return false;

        u = get(u), v = get(v);
        par[v] = u;
        return true;
    }
};

#define ONLINE_JUDGE
void solve() {
    memset(vis, -1, sizeof(vis));

    int r, c;
    cin >> r >> c;

    int cnt = 0;
    for(int i = 1; i <= r; i++) {
        for(int j = 1; j <= c; j++) {
            cin >> matrix[i][j];
        }
    }

    DSU dsu((r + 1) * (c +1) + 100);
    for(int i = 1; i <= r; i++) {
        for(int j = 1; j <= c; j++) {
            if(i +1 <= r && matrix[i][j] == matrix[i +1][j]) {
                dsu.unite(i * c + j, (i +1) * c + j);
            }
            if(j +1 <= c && matrix[i][j] == matrix[i][j +1]) {
                dsu.unite(i * c + j, i * c + j +1);
            }
        }
    }

    vector <int> vec;
    for(int i = 1; i <= r; i++) {
        for(int j = 1; j <= c; j++) {
            if(dsu.get(i * c + j) == i * c + j) {
                vec.emplace_back(i * c + j);
            }
        }
    }

    int cntc = 0;
    for(int &i : vec) {
        comp[i] = cntc++;
    }

    for(int i = 1; i <= r; i++) {
        for(int j = 1; j <= c; j++) {
            if(i +1 <= r && matrix[i][j] != matrix[i +1][j] && matrix[i][j] != '*' && matrix[i +1][j] != '*') {
                adj[comp[dsu.get(i * c + j)]].emplace(comp[dsu.get((i +1) * c + j)]);
            }
            if(j +1 <= c && matrix[i][j] != matrix[i][j +1] && matrix[i][j] != '*' && matrix[i][j +1] != '*') {
                adj[comp[dsu.get(i * c + j)]].emplace(comp[dsu.get(i * c + j +1)]);
            }
        }
    }

    priority_queue <pair <int, int>, vector <pair <int, int>>, greater <>> q;
    q.emplace(1, 0);
    while(!q.empty()) {
        auto [d, x] = q.top();
        q.pop();
        if(vis[x] != -1) {
            continue;
        }
        vis[x] = d;

        for(const int child : adj[x]) {
            if(vis[child] == -1) {
                q.emplace(d +1, child);
            }
        }
    }

    cout << *max_element(vis, vis + 1005 * 1005);
    
    return;
}

signed main() {
    #ifndef ONLINE_JUDGE
        freopen(".in", "r", stdin);
        freopen(".out", "w", stdout);
    #endif

    ios_base::sync_with_stdio(false);
    cin.tie(NULL); cout.tie(NULL);

    int t = 1; //cin >> t;
    for(int i = 1; i <= t; i++) {
        solve();
    }

    return 0;
}

Compilation message (stderr)

zoo.cpp: In function 'void solve()':
zoo.cpp:47:9: warning: unused variable 'cnt' [-Wunused-variable]
   47 |     int cnt = 0;
      |         ^~~

• Subtask 1: 0 / 45
• Subtask 2: 0 / 65