Submission #886895

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
886895	2023-12-13T06:44:49 Z	vjudge1	Usmjeri (COCI17_usmjeri)	C++17	0 / 140	2000 ms	262144 KB

usmjeri

#include <bits/stdc++.h>
using namespace std;
using i64 = long long;

const int MOD = 1E9 + 7;

const int MAXN = 3E5 + 5;
const int LOG = 25;

int p[LOG][MAXN];
int depth[MAXN], tin[MAXN], tout[MAXN];

int get(int a, int b) {
    for(int i = LOG -1; i >= 0; i--) {
        if(b & (1 << i)) {
            a = p[i][a];
        }
    }

    return a;
}

int par[MAXN];
struct DSU {
    int n;
    DSU(int n) : n(n) {
        // 23 orz
        iota(par, par + n, 0);
    }

    int get(int x) {
        if(par[x] == x) {
            return x;
        }

        return par[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[u] = v;

        return true;
    }
};

int lca(int a, int b) {
    if(depth[a] > depth[b]) {
        swap(a, b);
    }

    b = get(b, depth[b] - depth[a]);
    if(a == b) {
        return a;
    }

    for(int lg = LOG -1; lg >= 0; lg--) {
        if(p[lg][a] != p[lg][b]) {
            a = p[lg][a];
            b = p[lg][b];
        }
    }

    return p[0][a];
}

vector <pair <int, int>> adj[MAXN];
vector <pair <int, int>> bdj[MAXN];
map <pair <int, int>, int> edges;

pair <int, int> mp(int a, int b) {
    return {min(a, b), max(a, b)};
}

#define ONLINE_JUDGE
void solve() {
    int n, m;
    cin >> n >> m;

    for(int i = 1; i <= n -1; i++) {
        int u, v;
        cin >> u >> v;

        adj[u].emplace_back(v, i);
        adj[v].emplace_back(u, i);
        edges[mp(u, v)] = i;
    }

    int timer = 0;
    function <void(int, int)> dfs = [&](int node, int par) -> void {
        tin[node] = timer++;
        
        p[0][node] = par;
        depth[node] = depth[par] +1;
        for(auto &[child, col] : adj[node]) {
            if(child != par) {
                dfs(child, node);
            }
        }

        tout[node] = timer++;
    };

    dfs(1, 0);

    for(int lg = 1; lg < LOG; lg++) {
        for(int i = 1; i <= n; i++) {
            p[lg][i] = p[lg -1][p[lg -1][i]];
        }
    }

    DSU dsu(n +1);
    function <void(int, int)> merge = [&](int node, int par) -> void {
        vector <int> vec;
        while(node != par) {
            vec.emplace_back(edges[mp(node, p[0][node])]);
            node = p[0][node];
        }

        for(int i = 0; i +1 < int(vec.size()); i++) {
            bdj[vec[i]].emplace_back(vec[i +1], 0);
        }

        return;
    };

    vector <array <int, 3>> queries(m +1);
    for(int i = 1; i <= m; i++) {
        int a, b;
        cin >> a >> b;

        if(tout[a] < tout[b]) {
            swap(a, b);
        }


        int c = lca(a, b);
        queries[i] = {a, b, c};

        if(a != c) {
            merge(a, c);
        }
        
        if(b != c) {
            merge(b, c);
        }
        
        if(a != c && b != c) {
            bdj[edges[mp(a, p[0][a])]].emplace_back(edges[mp(b, p[0][b])], 1);
            bdj[edges[mp(b, p[0][b])]].emplace_back(edges[mp(a, p[0][a])], 1);
        }
    }

    vector <int> colors(n +1, -1);
    function <void(int, int, int)> paint = [&](int node, int par, int color) -> void {
        colors[node] = color;
        for(auto [child, c] : bdj[node]) {
            dsu.unite(node, child);
            if(colors[child] == -1) {
                paint(child, node, color ^ c);
            } else {
                if(colors[child] != color ^ c) {
                    cout << 0;
                    exit(0);
                }
            }
        }
    };

    for(int i = 1; i <= n; i++) {
        if(colors[i] == -1) {
            paint(i, 0, 0);
        }
    }

    int ans = 1;
    for(int i = 1; i <= n -1; i++) {
        if(dsu.get(i) == i) {
            ans = (ans * 2) % MOD;
        }
    }

    cout << ans;
    
    return;
}

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

usmjeri.cpp: In lambda function:
usmjeri.cpp:172:34: warning: suggest parentheses around comparison in operand of '^' [-Wparentheses]
  172 |                 if(colors[child] != color ^ c) {

Subtask #1

0 / 14.0

#	Verdict	Execution time	Memory	Grader output
1	Runtime error	1643 ms	262144 KB	Execution killed with signal 9
2	Halted	0 ms	0 KB	-

Subtask #2

0 / 14.0

#	Verdict	Execution time	Memory	Grader output
1	Runtime error	1514 ms	262144 KB	Execution killed with signal 9
2	Halted	0 ms	0 KB	-

Subtask #3

0 / 14.0

#	Verdict	Execution time	Memory	Grader output
1	Incorrect	8 ms	45916 KB	Output isn't correct
2	Halted	0 ms	0 KB	-

Subtask #4

0 / 14.0

#	Verdict	Execution time	Memory	Grader output
1	Incorrect	7 ms	45916 KB	Output isn't correct
2	Halted	0 ms	0 KB	-

Subtask #5

0 / 14.0

#	Verdict	Execution time	Memory	Grader output
1	Incorrect	11 ms	46424 KB	Output isn't correct
2	Halted	0 ms	0 KB	-

Subtask #6

0 / 14.0

#	Verdict	Execution time	Memory	Grader output
1	Incorrect	12 ms	46424 KB	Output isn't correct
2	Halted	0 ms	0 KB	-

Subtask #7

0 / 14.0

#	Verdict	Execution time	Memory	Grader output
1	Execution timed out	2013 ms	160044 KB	Time limit exceeded
2	Halted	0 ms	0 KB	-

Subtask #8

0 / 14.0

#	Verdict	Execution time	Memory	Grader output
1	Execution timed out	2037 ms	176560 KB	Time limit exceeded
2	Halted	0 ms	0 KB	-

Subtask #9

0 / 14.0

#	Verdict	Execution time	Memory	Grader output
1	Execution timed out	2049 ms	182660 KB	Time limit exceeded
2	Halted	0 ms	0 KB	-

Subtask #10

0 / 14.0

#	Verdict	Execution time	Memory	Grader output
1	Execution timed out	2057 ms	177040 KB	Time limit exceeded
2	Halted	0 ms	0 KB	-