Submission #1041357

#	Time	Username	Problem	Language	Result	Execution time	Memory
1041357		vjudge1	Connecting Supertrees (IOI20_supertrees)	C++17	100 / 100	124 ms	24152 KiB

supertrees

#include "supertrees.h"
using namespace std;
#define AE(a,b) ans[a][b]=ans[b][a]=1
struct dsu {
    int par[1010];
    int abp(int n){
        return par[n]?par[n]=abp(par[n]):n;
    }
    void merge(int a,int b){
        a=abp(a+1);
        b=abp(b+1);
        if(a-b)par[a]=b;
    }
    int CC(int n){
        return abp(n+1)-1;
    }
} comps, chains, CCs;
int construct(vector<vector<int>> p) {
    for(auto i:p)
        for(auto j:i)
            if(j==3)
                return 0;
    int n=p.size();
    vector<vector<int>>ans(n,vector<int>(n));
    for(int i=0;i<n;i++)
        for(int j=0;j<n;j++)
            if(p[i][j])
                CCs.merge(i,j);
    for(int i=0;i<n;i++)
        for(int j=0;j<n;j++)
            if(p[i][j]==1)
                chains.merge(i,j);
    for(int i=0;i<n;i++)
        for(int j=0;j<n;j++) if(p[i][j]==2)
            comps.merge(chains.CC(i),chains.CC(j));
    for(int i=0;i<n;i++)
        for(int j=0;j<n;j++)
            if(!p[i][j]) {
                if(CCs.CC(i)==CCs.CC(j))
                    return 0;
            } else if(p[i][j]==2)
                if(chains.CC(i)==chains.CC(j))
                    return 0;
    vector<int>thgs[1010];
    for(int i=0;i<n;i++)
        if(chains.CC(i)-i)
            AE(chains.CC(i),i);
        else thgs[comps.CC(i)].push_back(i);
    for(int i=0;i<n;i++){
        if(thgs[i].size()<2)continue;
        if(thgs[i].size()==2)return 0;
        thgs[i].push_back(thgs[i][0]);
        for(int j=1;j<thgs[i].size();j++)   
            AE(thgs[i][j],thgs[i][j-1]);
    }
    build(ans);
	return 1;
}

Compilation message (stderr)

supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:53:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   53 |         for(int j=1;j<thgs[i].size();j++)
      |                     ~^~~~~~~~~~~~~~~

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