Submission #318215

#	Time	Username	Problem	Language	Result	Execution time	Memory
318215		quocnguyen1012	Connecting Supertrees (IOI20_supertrees)	C++14	0 / 100	1 ms	364 KiB

supertrees

#ifdef LOCAL
#include <vector>
#include <cassert>
#include <cstdio>
#include <cstdlib>
#include <string>

static int n;
static std::vector<std::vector<int>> p;
static std::vector<std::vector<int>> b;
static bool called = false;

static void check(bool cond, std::string message) {
	if (!cond) {
		printf("%s\n", message.c_str());
		fclose(stdout);
		exit(0);
	}
}

void build(std::vector<std::vector<int>> _b) {
	check(!called, "build is called more than once");
	called = true;
	check((int)_b.size() == n, "Invalid number of rows in b");
	for (int i = 0; i < n; i++) {
		check((int)_b[i].size() == n, "Invalid number of columns in b");
	}
	b = _b;
}

#endif // LOCAL

#ifndef LOCAl
#include "supertrees.h"
#endif // LOCAl

#include <bits/stdc++.h>

#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define eb emplace_back

using namespace std;
typedef long long ll;
typedef pair<int, int> ii;

int construct(std::vector<std::vector<int>> p) {
  int N;
  vector<vector<int>> ans;
  vector<int> lab;

  N = p.size();
  ans = vector<vector<int>>(N, vector<int>(N));
  lab = vector<int>(N, -1);

  for (int i = 0; i < N; ++i) {
    for (int j = 0; j < N; ++j) {
      if (p[i][j] == 3) {
        return 0;
      }
    }
  }

  auto addedge = [&](int u, int v) {
    ans[u][v] = ans[v][u] = 1;
  };

  auto init = [&](void) {
    lab.assign(N, -1);
  };

  function<int(int)>findset = [&](int u) {
    if (lab[u] < 0) return u;
    return lab[u] = findset(lab[u]);
  };

  function<bool(int, int)>same = [&](int u, int v) {
    return findset(u) == findset(v);
  };

  function<void(int, int)>mergeset = [&](int u, int v) {
    u = findset(u); v = findset(v);
    if (u == v) return;
    if (lab[u] > lab[v]) swap(u, v);
    lab[u] += lab[v];
    lab[v] = u;
    return;
  };

  init();
  for (int i = 0; i < N; ++i) {
    for (int j = 0; j < N; ++j) {
      if (p[i][j] == 0 && same(i, j)) {
        return 0;
      }
      if (p[i][j])
        mergeset(i, j);
    }
  }

  init();
  vector<bool> used(N, false), ok(N, true);
  /// used is have cycle go through v

  for (int i = 0; i < N; ++i) {
    for (int j = i + 1; j < N; ++j) {
      if (p[i][j] == 1) ok[i] = false;
    }
  }


  for (int i = 0; i < N; ++i) {
    for (int j = 0; j < i; ++j) {
      if (p[i][j] == 1 && !same(i, j)) {
        addedge(i, j);
        mergeset(i, j);
      }
    }

    if (!ok[i]) continue;
    if (used[i]) continue;

    queue<int> q; q.push(i);
    used[i] = true;
    vector<int> cycle;
    while (q.size()) {
      int u = q.front(); q.pop();
      cycle.eb(u);
      for (int v = 0; v < N; ++v) {
        if (p[u][v] == 2 && !used[v] && ok[v]) {
          used[v] = true;
          q.push(v);
        }
      }
    }
    if (cycle.size() < 3)
      return 0;
    int n = cycle.size();
    for (int i = 0; i < n; ++i) {
      addedge(cycle[i], cycle[(i + 1) % n]);
      mergeset(cycle[i], cycle[(i + 1) % n]);
    }
  }
  build(ans);
  return 1;
}

#ifdef LOCAL
int main() {
#ifdef LOCAL
	freopen("A.INP", "r", stdin);
	freopen("A.OUT", "w", stdout);
#endif // LOCAL
	assert(scanf("%d", &n) == 1);

	p.resize(n);
	for (int i = 0; i < n; i++) {
		p[i].resize(n);
	}

	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			assert(scanf("%d", &p[i][j]) == 1);
		}
	}
	fclose(stdin);

	int possible = construct(p);

	check(possible == 0 || possible == 1, "Invalid return value of construct");
	if (possible == 1) {
		check(called, "construct returned 1 without calling build");
	} else {
		check(!called, "construct called build but returned 0");
	}

	printf("%d\n", possible);
	if (possible == 1) {
		for (int i = 0; i < n; i++) {
			for (int j = 0; j < n; j++) {
				if (j) {
					printf(" ");
				}
				printf("%d", b[i][j]);
			}
			printf("\n");
		}
	}
	fclose(stdout);
}
#endif // LOCAL

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