Submission #613813

#	Time	Username	Problem	Language	Result	Execution time	Memory
613813		drdilyor	Simurgh (IOI17_simurgh)	C++17	13 / 100	27 ms	468 KiB

simurgh

#include <bits/stdc++.h>
#include "simurgh.h"
#ifdef ONPC
    #include "t_debug.cpp"
#else
    #define debug(...) 42
#endif
#define sz(a) ((int)(a).size())
using namespace std;
using ll = long long;
const int INF = 1e9;
const ll INFL = 1e18;
const int RANDOM = chrono::high_resolution_clock::now().time_since_epoch().count();
mt19937 rng(RANDOM);
template<typename T, typename U> istream& operator>>(istream& is, pair<T, U>& p) { return is >> p.first >> p.second; }
const int N = 2e5, LOGN = 17, MOD = 1e9+7;

struct DSU {
    int n;
    vector<int> parent;
    vector<int> size;

    DSU(int n) : n(n), parent(n), size(n) {
        iota(parent.begin(), parent.end(), 0);
    }

    int get(int i) {
        return parent[i] == i ? i : parent[i] = get(parent[i]);
    }

    void merge(int v, int u) {
        v = get(v);
        u = get(u);
        if (u == v) return;
        if (size[v] < size[u]) swap(v, u);
        parent[v] = u;
        size[v] += size[u];
    }
};

vector<int> find_roads(int n, vector<int> u, vector<int> v) {
    int m = sz(u);
    vector<pair<int,int>> edges(m);
    for (int i = 0; i < m; i++) {
        edges.emplace_back(u[i], v[i]);
    }
    for (int i = 0; i < (1 << m); i++) {
        if (__builtin_popcount(i) != n - 1) continue;
        vector<int> cur;
        DSU cc(n);
        for (int j = 0; j < m; j++) {
            if (i & (1 << j)) {
                if (cc.get(u[j]) == cc.get(v[j]))
                    break;
                cc.merge(u[j], v[j]);
                cur.push_back(j);
            }
        }
        if (cur.size() == n-1 && count_common_roads(cur) == n-1) return cur;
    }

    assert(false);
}

/*
     █████               █████  ███  ████                               
    ▒▒███               ▒▒███  ▒▒▒  ▒▒███                               
  ███████  ████████   ███████  ████  ▒███  █████ ████  ██████  ████████ 
 ███▒▒███ ▒▒███▒▒███ ███▒▒███ ▒▒███  ▒███ ▒▒███ ▒███  ███▒▒███▒▒███▒▒███
▒███ ▒███  ▒███ ▒▒▒ ▒███ ▒███  ▒███  ▒███  ▒███ ▒███ ▒███ ▒███ ▒███ ▒▒▒ 
▒███ ▒███  ▒███     ▒███ ▒███  ▒███  ▒███  ▒███ ▒███ ▒███ ▒███ ▒███     
▒▒████████ █████    ▒▒████████ █████ █████ ▒▒███████ ▒▒██████  █████    
 ▒▒▒▒▒▒▒▒ ▒▒▒▒▒      ▒▒▒▒▒▒▒▒ ▒▒▒▒▒ ▒▒▒▒▒   ▒▒▒▒▒███  ▒▒▒▒▒▒  ▒▒▒▒▒     
                                            ███ ▒███                    
                                           ▒▒██████                     
                                            ▒▒▒▒▒▒
*/

Compilation message (stderr)

simurgh.cpp: In function 'std::vector<int> find_roads(int, std::vector<int>, std::vector<int>)':
simurgh.cpp:59:24: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   59 |         if (cur.size() == n-1 && count_common_roads(cur) == n-1) return cur;
      |             ~~~~~~~~~~~^~~~~~

• Subtask 1: 13 / 13
• Subtask 2: 0 / 17
• Subtask 3: 0 / 21
• Subtask 4: 0 / 19
• Subtask 5: 0 / 30