POJ2367 拓扑排序入门

拓扑排序入门题，此题基本正常的方法都能过，不需要判断是否存在环的情况。

#include <iostream>
#include <cstdio>
#include <algorithm>
using namespace std;

const int N = 105;
struct Edge
{
	int pos;
	int next;
};
int n;
int indeg[N];
Edge edge[N * N];
int cur;
int neigh[N];
int queue[N], front, rear;

void init()
{
	for (int i = 0; i < n; ++i)  neigh[i] = -1;
	cur = 0;
	front = rear = 0;
}

int main()
{
	int t, e;
	scanf("%d", &n);
	init();
	for (int i = 0; i < n; ++i)
	{
		while (scanf("%d", &t) && t)
		{
			++indeg[t - 1];
			edge[cur].pos = t - 1;
			edge[cur].next = neigh[i];
			neigh[i] = cur;
			++cur;
		}
	}
	for (int i = 0; i < n; ++i)
	{
		if (indeg[i] == 0)
		{
			queue[rear++] = i;
		}
	}
	bool beg = true;
	while (front != rear)
	{
		t = queue[front++];
		if (!beg) printf(" ");
		printf("%d", t + 1);
		beg = false;
		e = neigh[t];
		while (e != -1)
		{
			--indeg[edge[e].pos];
			if (indeg[edge[e].pos] == 0) queue[rear++] = edge[e].pos;
			e = edge[e].next;
		}
	}
	printf("\n");
	return 0;
}