Submission #309412

#	Time	Username	Problem	Language	Result	Execution time	Memory
309412		pere_gil	Connecting Supertrees (IOI20_supertrees)	C++14	0 / 100	1 ms	384 KiB

supertrees

#include "bits/stdc++.h"
#include "supertrees.h"

using namespace std;

int pos[1001];

void init(int n){
    for(int i=0;i<n;i++) pos[i]=i;
}

int findset(int a){
    if(pos[a]==a) return a;
    else findset(pos[a]);
}

void unionset(int A, int B){
    int a=findset(A);
    int b=findset(B);
    if(a!=b) pos[b]=a;
}

bool issameset(int a, int b){
    if(findset(a)==findset(b)) return true;
    else return false;
}

int construct(std::vector<std::vector<int>> p)
{
    int n = p.size();
    std::vector<std::vector<int>> answer;
    init(n);

    for(int i=0;i<n;i++){
        for(int j=0;j<n;j++){
            if(p[i][j]==1) unionset(i,j);
        }
    }

    vector<int> ja[n];
    for(int i=0;i<n;i++) ja[findset(i)].push_back(i);

    bool semamo=false;
    for(int i=0;i<n;i++){
        for(int j=0;j<n;j++){
            if(issameset(i,j) and p[i][j]==0) semamo=true;
        }
    }

    if(semamo) return 0;

    int res[n][n];
    memset(res,0,sizeof(res));
    for(int i=0;i<n;i++){
        for(int j=0;j<ja[i].size()-1;j++) res[ja[i][j]][ja[i][j+1]]=1;
    }

    for (int i = 0; i < n; i++) {
        std::vector<int> row;
        for(int j=0;j<n;j++) row.push_back(res[i][j]);
        row.resize(n);
        answer.push_back(row);
    }

    build(answer);
    return 1;

    return 0;
}

Compilation message (stderr)

supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:55:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   55 |         for(int j=0;j<ja[i].size()-1;j++) res[ja[i][j]][ja[i][j+1]]=1;
      |                     ~^~~~~~~~~~~~~~~
supertrees.cpp: In function 'int findset(int)':
supertrees.cpp:14:17: warning: control reaches end of non-void function [-Wreturn-type]
   14 |     else findset(pos[a]);
      |          ~~~~~~~^~~~~~~~

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