Submission #948276

#	Time	Username	Problem	Language	Result	Execution time	Memory
948276		steveonalex	Connecting Supertrees (IOI20_supertrees)	C++14	96 / 100	151 ms	24360 KiB

supertrees

#include <bits/stdc++.h>
#include "supertrees.h"
 
using namespace std;
 
typedef long long ll;
typedef unsigned long long ull;
 
#define MASK(i) (1ULL << (i))
#define GETBIT(mask, i) (((mask) >> (i)) & 1)
#define ALL(v) (v).begin(), (v).end()
 
ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}
 
ll LASTBIT(ll mask){return (mask) & (-mask);}
int pop_cnt(ll mask){return __builtin_popcountll(mask);}
int ctz(ll mask){return __builtin_ctzll(mask);}
int logOf(ll mask){return 63 - __builtin_clzll(mask);}
 
mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rngesus(ll l, ll r){return l + (ull) rng() % (r - l + 1);}
 
template <class T1, class T2>
    bool maximize(T1 &a, T2 b){
        if (a < b) {a = b; return true;}
        return false;
    }
 
template <class T1, class T2>
    bool minimize(T1 &a, T2 b){
        if (a > b) {a = b; return true;}
        return false;
    }
 
template <class T>
    void printArr(T& container, string separator = " ", string finish = "\n", ostream &out = cout){
        for(auto item: container) out << item << separator;
        out << finish;
    }
 
template <class T>
    void remove_dup(vector<T> &a){
        sort(ALL(a));
        a.resize(unique(ALL(a)) - a.begin());
    }

struct DSU{
    int n;
    vector<int> parent, sz;

    DSU(int _n){
        n = _n;
        parent.resize(n); sz.resize(n, 1);
        for(int i = 0; i<n; ++i) parent[i] = i;
    }

    int find_set(int u){return (u == parent[u]) ? u : (parent[u] = find_set(parent[u]));}
    bool same_set(int u, int v){return find_set(u) == find_set(v);}

    bool join_set(int u, int v){
        u = find_set(u), v = find_set(v);
        if (u != v){
            if (sz[u] < sz[v]) swap(u, v);
            parent[v] = u;
            sz[u] += sz[v];
            return true;
        }
        return false;
    }
};

// void build(vector<vector<int>> p){
//     cout << "Answer: \n";
//     for(int i = 0; i<p.size(); ++i) printArr(p[i]);
// }

const int N = 1009;

vector<int> crew[N];

int construct(vector<vector<int>> p) {
    int n = p.size();
    vector<vector<int>> ans(n, vector<int>(n));

    for(int i = 0; i<n; ++i) crew[i].clear();

    DSU chode(n);
    for(int i = 0; i<n; ++i) for(int j = i+1; j<n; ++j) if (p[i][j]) chode.join_set(i, j);
    for(int i = 0; i<n; ++i) for(int j = i+1; j<n; ++j) if (p[i][j] == 0 && chode.same_set(i, j)) return 0; 

    for(int i = 0; i<n; ++i) crew[chode.find_set(i)].push_back(i);

    DSU sigma(n);
    for(int i= 0; i<n; ++i) for(int j = i+1; j<n; ++j) if (p[i][j] == 1) sigma.join_set(i, j);

    for(int i = 0; i<n; ++i) if (crew[i].size()){
        vector<int> pos;
        for(int j: crew[i]) if (j != sigma.find_set(j)) {
            int k = sigma.find_set(j);
            ans[j][k] = ans[k][j] = 1;
        }
        else pos.push_back(j);

        if (pos.size() == 1) continue;
        if (pos.size() == 2) return 0;
        int m = pos.size();
        for(int x: pos) for(int y: crew[i]) if (x != y && x != sigma.find_set(y))
            if (p[x][y] != p[pos[0]][pos[1]]) return 0;
        int deg = p[pos[0]][pos[1]];
        if (pos.size() <= deg) return 0;
        for(int i = 0; i<m; ++i) {
            int j = (i + 1) % m;
            ans[pos[i]][pos[j]] = ans[pos[j]][pos[i]] = 1;
        }
        if (deg == 3){
            ans[pos[0]][pos[2]] = ans[pos[2]][pos[0]] = 1;
        }
    }

    build(ans);
    return 1;
}

 
// int main(void){
//     ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
//     construct({{1, 1, 2, 2}, {1, 1, 2, 2}, {2, 2, 1, 2}, {2, 2, 2, 1}});
//     return 0;
// }

Compilation message (stderr)

supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:111:24: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
  111 |         if (pos.size() <= deg) return 0;
      |             ~~~~~~~~~~~^~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 10 / 10
• Subtask 3: 19 / 19
• Subtask 4: 35 / 35
• Subtask 5: 21 / 21
• Subtask 6: 0 / 4