Submission #461280

#	Time	Username	Problem	Language	Result	Execution time	Memory
461280		armand	슈퍼트리 잇기 (IOI20_supertrees)	C++14	11 / 100	231 ms	26012 KiB

supertrees

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

int pp[1001][1001];
int n;
std::vector<std::vector<int>> answer;

bool all1()
{
	int i, j;
	for (i = 0; i < n; i++)
		for (j = 0; j < n; j++)
			if (pp[i][j] != 1)
				return false;
	return true;
}

bool all01()
{
	int i, j;
	for (i = 0; i < n; i++)
		for (j = 0; j < n; j++)
			if (pp[i][j] > 1)
				return false;
	return true;
}

void solve1()
{
	int i;
	for (i = 0; i < n - 1; i++) {
		answer[i][i + 1] = 1;
		answer[i + 1][i] = 1;
	}
}

int color[1001];
int nodes[1001];
int nn;
bool flag2;
void dfs(int u, int prnt)
{
	int j;
	if (prnt == -1) {
		std::vector<int> v;
		for (j = 0; j < n; j++)
			if (pp[u][j])
				v.push_back(j);
		for (j = 0; j < v.size() - 1; j++)
			if (!pp[v[j]][v[j + 1]])
				flag2 = false;
		if (v.size() > 1 && !pp[v[0]][v.size() - 1])
			flag2 = false;
	}
	for(j=0; j<n; j++)
		if (pp[u][j] && !color[j]) {
			nodes[nn++] = j;
			color[j] = 1;
			if (prnt != -1 && !pp[j][prnt])
				flag2 = false;
			dfs(j, u);
		}
}

void solve2()
{
	int i, j;
	for (i = 0; i < n; i++) {
		if (!color[i]) {
			nn = 0;
			color[i] = 1;
			dfs(i, -1);
			for (j = 1; j < nn; j++) {
				answer[nodes[j]][nodes[j - 1]] = 1;
				answer[nodes[j - 1]][nodes[j]] = 1;
			}
		}
	}
}

int construct(std::vector<std::vector<int>> p)
{
	n = p.size();
	int i, j;
	for (i = 0; i < n; i++)
		for (j = 0; j < n; j++)
			pp[i][j] = p[i][j];
	for (int i = 0; i < n; i++) {
		std::vector<int> row;
		row.resize(n);
		answer.push_back(row);
	}
	if (all1())
		solve1();
	else if (all01()) {
		flag2 = true;
		solve2();
		if (flag2) {
			build(answer);
			return 1;
		}
		else
			return 0;
	}
	build(answer);
	return 1;
}

Compilation message (stderr)

supertrees.cpp: In function 'void dfs(int, int)':
supertrees.cpp:49:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   49 |   for (j = 0; j < v.size() - 1; j++)
      |               ~~^~~~~~~~~~~~~~

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