POJ2367 Genealogical tree(拓扑排序)

题意：

就是最简单的拓扑排序，裸题

要点：

裸题，直接模板一套就行

15174030

Seasonal

2367

Accepted

188K

0MS

C++

734B

2016-02-18 17:08:31

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
int c[150],topo[150];
int t,n;
bool g[150][150];

bool dfs(int u)
{
	c[u] = -1;
	for (int v = 1; v <= n; v++)
	{
		if (g[u][v])
		{
			if (c[v] == -1) return false;
			else if (!c[v] && !dfs(v)) return false;
		}
	}
	c[u] = 1;
	topo[--t] = u;
	return true;
}
bool toposort()
{
	t = n;
	memset(c, 0, sizeof(c));
	for (int i = 1; i <= n; i++)
		if (!c[i] && !dfs(i))
			return false;
	return true;
}
int main()
{
	int u, v;
	scanf("%d", &n);
	memset(g, false, sizeof(g));
	for (u = 1; u <= n; u++)
	{
		while (~scanf("%d", &v), v)
			g[u][v] = true;
	}
	if (toposort())
	{
		for (int i = 0; i < n - 1; i++)
			printf("%d ", topo[i]);
		printf("%d\n", topo[n - 1]);
	}
	return 0;
}