Submission #309382

#	Time	Username	Problem	Language	Result	Execution time	Memory
309382		georgerapeanu	Connecting Supertrees (IOI20_supertrees)	C++17	11 / 100	252 ms	22140 KiB

supertrees

#include "supertrees.h"
#include <vector>

using namespace std;

struct dsu_t{
    int n;
    int father[1005];

    dsu_t(int n){
        this->n = n;
        for(int i = 0;i < n;i++){
            father[i] = -1;
        }
    }

    int find_root(int nod){
        if(father[nod] == -1){
            return nod;
        }
        return father[nod] = find_root(father[nod]);
    }

    bool unite(int x,int y){
        x = find_root(x);
        y = find_root(y);

        if(x == y){
            return false;
        }

        father[x] = y;
        return true;
    }
};

int construct(vector<vector<int>> p) {
	int n = p.size();
	vector<vector<int>> answer(n,vector<int>(n,0));

    dsu_t dsu(n);

	for (int i = 0; i < n; i++) {
	    for(int j = 0;j < n;j++){
            if(p[i][j] == 3){
                return 0;
            }
            else if(p[i][j] == 1){
                if(dsu.unite(i,j)){
                    answer[i][j] = answer[j][i] = 1;
                }
            }
        }
    }
	for (int i = 0; i < n; i++) {
	    for(int j = 0;j < n;j++){
            if(p[i][j] == 2 || p[i][j] == 0){
                if(dsu.find_root(i) == dsu.find_root(j)){
                    return 0;
                }
            }
        }
    }

    vector<int> roots;

    for(int i = 0;i < n;i++){
        if(dsu.find_root(i) == i){
            roots.push_back(i);
        }
    }

    if(roots.size() == 2){
        return 0;
    }

    if(roots.size() > 2){
        for(int i = 0;i < (int)roots.size();i++){
            answer[roots[i]][roots[(i + 1) % roots.size()]] = 1;
            answer[roots[(i + 1) % roots.size()]][roots[i]] = 1;
        }
    }

	build(answer);
	return 1;
}

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