# | 제출 시각 | 아이디 | 문제 | 언어 | 결과 | 실행 시간 | 메모리 |
---|---|---|---|---|---|---|---|
1196122 | islam_2010 | 슈퍼트리 잇기 (IOI20_supertrees) | C++20 | 0 ms | 0 KiB |
#include <bits/stdc++.h>
using namespace std;
bool solve(vector<vector<int>>& p) {
int n = p.size();
for (int i = 0; i < n; ++i) {
if (p[i][i] != 1) return false;
for (int j = 0; j < n; ++j) {
if (p[i][j] != p[j][i]) return false;
if (p[i][j] > 2) return false;
}
}
vector<vector<int>> b(n, vector<int>(n, 0));
vector<int> parent(n);
for (int i = 0; i < n; ++i) parent[i] = i;
auto find = [&](int u) {
while (parent[u] != u) {
parent[u] = parent[parent[u]];
u = parent[u];
}
return u;
};
for (int i = 0; i < n; ++i) {
for (int j = i + 1; j < n; ++j) {
if (p[i][j] == 1) {
int root_i = find(i);
int root_j = find(j);
if (root_i == root_j) {
return false;
}
parent[root_j] = root_i;
b[i][j] = b[j][i] = 1;
}
}
}
for (int i = 0; i < n; ++i) {
for (int j = i + 1; j < n; ++j) {
if (p[i][j] == 2) {
if (find(i) != find(j)) {
return false;
}
bool found = false;
for (int k = 0; k < n; ++k) {
if (k != i && k != j && b[i][k] == 1 && b[k][j] == 1) {
found = true;
break;
}
}
if (!found) {
return false;
}
}
}
}
return true;
}
int construct(vector<vector<int>> p) {
if (!solve(p)) {
return 0;
}
int n = p.size();
vector<vector<int>> b(n, vector<int>(n, 0));
vector<int> parent(n);
for (int i = 0; i < n; ++i) parent[i] = i;
auto find = [&](int u) {
while (parent[u] != u) {
parent[u] = parent[parent[u]];
u = parent[u];
}
return u;
};
for (int i = 0; i < n; ++i) {
for (int j = i + 1; j < n; ++j) {
if (p[i][j] == 1) {
int root_i = find(i);
int root_j = find(j);
parent[root_j] = root_i;
b[i][j] = b[j][i] = 1;
}
}
}
for (int i = 0; i < n; ++i) {
for (int j = i + 1; j < n; ++j) {
if (p[i][j] == 2 && b[i][j] == 0) {
bool added = false;
for (int k = 0; k < n; ++k) {
if (k != i && k != j && b[i][k] == 1 && b[k][j] == 1) {
added = true;
break;
}
}
if (!added) {
b[i][j] = b[j][i] = 1;
}
}
}
}
build(b);
return 1;
}