Submission #1090025

#	Time	Username	Problem	Language	Result	Execution time	Memory
1090025		onlk97	Connecting Supertrees (IOI20_supertrees)	C++14	0 / 100	1 ms	348 KiB

supertrees

#include "supertrees.h"
#include <vector>
#include <bits/stdc++.h>
using namespace std;
struct DSU{
    vector <int> dsu;
    void init(int n){
        dsu.clear();
        for (int i=0; i<=n; i++) dsu.push_back(i);
    }
    int prt(int n){
        if (dsu[n]==n) return n;
        return dsu[n]=prt(dsu[n]);
    }
    void unn(int u,int v){
        dsu[prt(u)]=dsu[prt(v)];
    }
};
int construct(vector <vector <int> > p){
    int n=p.size();
    DSU d;
    d.init(n);
    vector <vector <int> > op(n,vector <int>(n,0));
    for (int i=0; i<n; i++){
        for (int j=i+1; j<n; j++){
            if (p[i][j]==1){
                d.unn(i,j);
                op[i][j]=1; op[j][i]=1;
            }
            if (p[i][j]==3) return 0;
        }
    }
    for (int i=0; i<n; i++){
        for (int j=i+1; j<n; j++){
            if ((p[i][j]==1)!=(d.prt(i)==d.prt(j))) return 0;
        }
    }
    for (int i=0; i<n; i++){
        if (p[i]!=p[d.prt(i)]) return 0;
    }
    bool done[n];
    for (int i=0; i<n; i++) done[i]=0;
    for (int i=0; i<n; i++){
        if (d.prt(i)!=i||done[i]) continue;
        set <int> s;
        s.insert(d.prt(i));
        for (int j=i+1; j<n; j++){
            if (p[i][j]==2) s.insert(d.prt(j));
        }
        if (s.size()<3) return 0;
        vector <int> vec;
        for (int j:s) vec.push_back(j);
        for (int j=0; j<s.size(); j++){
            op[vec[j]][vec[(j+1)%s.size()]]=1; op[vec[(j+1)%s.size()]][vec[j]]=1;
        }
        for (int j:vec){
            done[j]=1;
            for (int k=0; k<n; k++){
                if (p[j][k]==2&&s.find(d.prt(k))==s.end()) return 0;
            }
        }
    }
    build(op);
    return 1;
}

Compilation message (stderr)

supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:53:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::set<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   53 |         for (int j=0; j<s.size(); j++){
      |                       ~^~~~~~~~~

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