Submission #315388

#	Time	Username	Problem	Language	Result	Execution time	Memory
315388		nickmet2004	Connecting Supertrees (IOI20_supertrees)	C++14	0 / 100	1 ms	384 KiB

supertrees

#include<bits/stdc++.h>
#include "supertrees.h"
using namespace std;

int construct(vector<vector<int>>p){
    int n = p.size();
    vector<vector<int>>ans(n) , E(n); vector<int> Q(n) , cmp(n) , ch(n) , vis(n);
    for(int i = 0; i< n; ++i) for(int j = 0; j< n; ++j) if(p[i][j] == 3 || p[i][j] != p[j][i]) return 0;
    for(int i = 0; i < n; ++i)ans[i].resize(n);
    int cnt = 0;
    for(int i = 0; i < n; ++i){
        if(cmp[i]) continue;
        cmp[i] = ++cnt;
        for(int j = 0; j < n; ++j) if(p[i][j])cmp[j] = cmp[i];
    }
    /// components
    for(int i = 0; i < n; ++i) for(int j = 0; j < n; ++j) if((cmp[i] == cmp[j])  ^ (p[i][j]!=0))return 0;
    cnt =0;
    for(int i= 0; i < n; ++i){
        if(ch[i])continue;
        ch[i] = ++cnt;
        for(int j = 0; j< n; ++j) if(p[i][j] == 1) E[i].emplace_back(j) , ch[j] = ch[i];
    }
    /// determine double cycles
    for(int i = 0; i < n; ++i) for(int j = 0; j < n; ++j) if((ch[i] == ch[j]) ^ (p[i][j] == 1))return 0;
    for(int i = 0; i < n; ++i){
        if(!E[i].size())continue;
        Q.emplace_back(i);
        for(int j : E[i]) ans[i][j] = ans[j][i] = 1;
    }
    /// make a cycle
    for(int i : Q){
        if(vis[i])continue;
        vector<int> a;
        for(int j : Q){
            if(cmp[i] == cmp[j]) a.emplace_back(j) , vis[j] = 1;
        }
        if(a.size() == 2) return 0;
        if(a.size() == 1)continue;
        for(int k = 0; k < a.size(); ++k){
            int X = a[k] , Y = a[(k + 1) % a.size()];
            if(X^Y)
            ans[X][Y] = ans[Y][X]= 1;
        }
    }    
    build(ans);
}

Compilation message (stderr)

supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:40:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   40 |         for(int k = 0; k < a.size(); ++k){
      |                        ~~^~~~~~~~~~
supertrees.cpp:7:29: warning: control reaches end of non-void function [-Wreturn-type]
    7 |     vector<vector<int>>ans(n) , E(n); vector<int> Q(n) , cmp(n) , ch(n) , vis(n);
      |                             ^

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