Submission #315716

#	Time	Username	Problem	Language	Result	Execution time	Memory
315716		nickmet2004	Connecting Supertrees (IOI20_supertrees)	C++14	0 / 100	4 ms	672 KiB

supertrees

#include<bits/stdc++.h>
#pragma GCC optimize("Ofast")
#include "supertrees.h"
using namespace std;
const int N = 1005;
int cmp[N] , cnt , ch[N] , papa[N] , vis[N];
vector<vector<int>> ans;
vector<int> Q , a;
int construct(vector<vector<int>> p){
    int n = p.size();
    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;
    ans.resize(n);
    for(int i = 0; i < n; ++i) ans[i].resize(n);
    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;
    memset(papa , -1 , sizeof(papa));
    for(int i = 0; i < n; ++i){
        if(ch[i]) continue;
        ch[i] = ++cnt; Q.emplace_back(i);
        for(int j = 0; j < n; ++j) if(p[i][j] == 1) papa[j] = i , ch[j] = ch[i];
    }
    /// multiple 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(papa[i] != i && papa[i] >= 0) ans[i][papa[i]] = ans[papa[i]][i] = 1;
    for(int &i : Q){
        if(vis[i])continue;
        a.resize(0);
        for(int &j : Q) if(cmp[i] == cmp[j]) vis[j] = 1 , a.push_back(j);
        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:37:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   37 |         for(int k= 0; k < a.size(); ++k){
      |                       ~~^~~~~~~~~~
supertrees.cpp:43:10: warning: control reaches end of non-void function [-Wreturn-type]
   43 |     build(ans);
      |     ~~~~~^~~~~

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