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Submission #199172

# Submission time Handle Problem Language Result Execution time Memory
199172 2020-01-29T19:43:52 Z Bagritsevich_Stepan Easter Eggs (info1cup17_eastereggs) C++14
100 / 100
 38 ms 380 KB 
#include <bits/stdc++.h>
#include "grader.h"

using namespace std;

#define mp make_pair
#define pb push_back
#define fast_io ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define pii pair < int, int >
#define fs first
#define sc second
#define getfiles ifstream cin("input.txt"); ofstream cout("output.txt");
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()

typedef long long ll;
typedef long double ld;

const int maxn = 2055;
vector < int > g[maxn], islands;
int verts[maxn], timer;
bool used[maxn];

void dfs(int v) {
    used[v] = true;
    verts[timer++] = v;
    
    for (int j = 0; j < sz(g[v]); j++) {
        int to = g[v][j];
        if (!used[to])
            dfs(to);
    }
}

bool prov(int max_ind) {
    islands.clear();
    for (int i = 0; i <= max_ind; i++)
        islands.pb(verts[i] + 1);
    
    return query(islands);
}

int bin_search() {
    int l = -1, r = timer - 1;
    while (r - l > 1) {
        int m = (l + r) / 2;
        if (prov(m))
            r = m;
        else
            l = m;
    }
    
    return verts[r] + 1;
}

int findEgg(int n, vector < pii > bridges) {
    for (int i = 0; i < n; i++) {
        g[i].clear();
        used[i] = false;
    }
    
    for (int i = 0; i < sz(bridges); i++) {
        int u = bridges[i].fs, v = bridges[i].sc;
        u--;
        v--;
        
        g[u].pb(v);
        g[v].pb(u);
    }
    
    timer = 0;
    dfs(0);
    
    return bin_search();
}

Subtask #1
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 244 KB Number of queries: 4
2 Correct 6 ms 376 KB Number of queries: 4
3 Correct 6 ms 376 KB Number of queries: 4
4 Correct 6 ms 376 KB Number of queries: 4

Subtask #2
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 14 ms 300 KB Number of queries: 8
2 Correct 20 ms 380 KB Number of queries: 9
3 Correct 22 ms 300 KB Number of queries: 9
4 Correct 26 ms 376 KB Number of queries: 9

Subtask #3
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 28 ms 376 KB Number of queries: 9
2 Correct 19 ms 300 KB Number of queries: 9
3 Correct 22 ms 280 KB Number of queries: 9
4 Correct 38 ms 376 KB Number of queries: 9