Submission #389242

#	Time	Username	Problem	Language	Result	Execution time	Memory
389242		cheissmart	Easter Eggs (info1cup17_eastereggs)	C++14	10 / 100	20 ms	472 KiB

eastereggs

#include <bits/stdc++.h>
#include "grader.h"
#define F first
#define S second
#define V vector
#define PB push_back
#define EB emplace_back
#define MP make_pair
#define ALL(v) (v).begin(), (v).end()
#define debug(x) cerr << "LINE(" << __LINE__ << "): " << #x << " is " << x << endl

using namespace std;

typedef long long ll;
typedef pair<int, int> pi;
typedef V<int> vi;

const int INF = 1e9 + 7, N = 520;

vi G[N];
int vis[N], sz[N], tot;

void init(int n) {
    for(int i = 1; i <= n; i++) {
        G[i].clear();
        vis[i] = 0;
    }
}

int dfs_sz(int u, int p = 0) {
    sz[u] = 1;
    for(int v:G[u]) if(v != p && !vis[v]) {
        sz[u] += dfs_sz(v, u);
    }
    return sz[u];
}

int get_c(int u, int p = 0) {
    int mx = 0;
    for(int v:G[u]) if(v != p && !vis[v]) {
        int cc = get_c(v, u);
        mx = max(mx, sz[v]);
        if(cc) return cc;
    }
    if(max(mx, tot - sz[u]) * 2 <= tot) return u;
    return 0;
}

vi s;

void dfs(int u, int p) {
    s.PB(u);
    for(int v:G[u]) if(v != p && !vis[v]) dfs(v, u);
}

int go(int u) {
    tot = dfs_sz(u);
    int c = get_c(u);
    for(int v:G[c]) if(!vis[v]) {
        s.clear();
        dfs(v, c);
        if(query(s)) {
            vis[c] = 1;
            return go(v);
        }
    }
    return c;
}

int findEgg(int n, V<pi> es) {
    init(n);
    for(pi p:es) G[p.F].PB(p.S), G[p.S].PB(p.F);
    return go(1);
}

• Subtask 1: 10 / 40
• Subtask 2: 0 / 40
• Subtask 3: 0 / 20