Submission #315377

#	Time	Username	Problem	Language	Result	Execution time	Memory
315377		nickmet2004	Connecting Supertrees (IOI20_supertrees)	C++14	Compilation error	0 ms	0 KiB

supertrees

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

const int N = 1000;
int n , p[N][N], cmp[N] , ch[N] , vis[N];
vector<int> E[N] , Q;
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;
    for(int i = 0; i < n; ++i)adj[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])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;
    vector<vector<int>>ans(n);
    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(p[i][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()];
            ans[X][Y] = ans[Y][X]= 1;
        }
    }for(int i = 0; i < n; ++i)ans[i][i] =0;
    build(ans);
}

Compilation message (stderr)

supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:11:31: error: 'adj' was not declared in this scope
   11 |     for(int i = 0; i < n; ++i)adj[i].resize(n);
      |                               ^~~
supertrees.cpp:43:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   43 |         for(int k = 0; k < a.size(); ++k){
      |                        ~~^~~~~~~~~~
supertrees.cpp:28:29: warning: control reaches end of non-void function [-Wreturn-type]
   28 |     vector<vector<int>>ans(n);
      |                             ^